読者からよく寄せられる質問のひとつがある：「WordPressでプラグインを追加できないのはなぜですか？
このような状況は通常、アップグレードのメッセージが表示されたり、管理画面にプラグインメニューがない場合に起こります。もしあなたがこの問題に対処しているなら、この記事で最も一般的な理由を説明します。
WordPressでプラグインの追加やインストールができない理由については、こちらをお読みください。
このガイドでは、WordPressにプラグインを追加またはインストールできない主な理由を5つ挙げています。以下のクイックリンクを使用して、あなたの状況に当てはまる特定のトピックにスキップしてください：
1.WordPress.comをご利用中です。
WordPress.comは、人気のあるインストール型のWordPressソフトウェアの限定バージョンを提供するブログホスティングサービスです。詳しくはWordPress.comとWordPress.orgの違いをご覧ください。
WordPress.comユーザーは、月額10ドルからのビジネスプラン以上にアップグレードしない限り、プラグインをインストールすることはできません。Free、Personal、またはPremiumプランの場合は、サードパーティ製のプラグインをインストールすることはできません。
その金額を支払いたくないのであれば、WordPress.comからWordPress.orgにブログを移行することができる。
WordPressブログのセットアップが必要な場合は、無料のWordPressブログセットアップサービスをご利用ください。サイトの移管をご希望とお知らせいただければ、無料で移管いたします。
プロのヒント WordPress.orgで手間なくサイトを作りたいですか？私たちのWPBeginnerプロサービスは、あなたのオンラインプレゼンスを開始し、労力をかけずに美しいサイトを構築するのに役立ちます。
2.ユーザー権限グループに制限がある。
WordPressには、サイト上のユーザーにさまざまなレベルのアクセス権を割り当てるユーザー権限管理システムがビルトインされています。
管理者は WordPress サイトのすべての機能（プラグインの追加、インストール、有効化など）にアクセスできる最高のユーザー権限です。
一方、エディター、投稿者、寄稿者、購読者はプラグインをインストールできません。
サイト上で作業しているにもかかわらず「プラグイン」メニューが表示されない場合は、管理者にアクセス権がない可能性があります。
この場合、サイトを管理している人（開発者やウェブマスターなど）を信頼しているのであれば、必要なプラグインをインストールするための管理者権限を与えてくれるよう、丁重にお願いすることができる。
3.メモリ制限の問題
2番目によくあるシナリオは、プラグインページは表示されアクセスできるのに、プラグインをインストールできないというものです。プラグインをインストールしようとすると、エラーメッセージが表示されます。
このエラーは通常、PHPのメモリ制限によって引き起こされます。WordPressはPHPスクリプト言語を使って書かれており、各PHPスクリプトは一定量のメモリを使用します。
WordPressホスティングとWordPressコアには、PHPスクリプトが使用できるメモリ量を定義する設定があります。
プロセスがこの制限に達すると、終了するか、WordPressサイトにこのようなエラーが表示される：
致命的エラー：許容メモリサイズ 67108864 バイトを使い果たした。
この問題を素早く解決するには、PHPのメモリ制限を増やすことです。それには、wp-config.phpファイルに次の行を追加します：
define('WP_MEMORY_LIMIT', '256M');
より詳細な手順については、WordPressのメモリを使い果たしたエラーの修正方法をご覧ください。
PHPのメモリ制限を増やすことで問題を解決し、プラグインをインストールできるようになる場合もありますが、必ずしも理想的な解決策ではないことを理解しておきましょう。
悪意のあるコードが高いメモリ制限を悪用して意図した以上のリソースを消費し、WordPressサイトのセキュリティに影響を与える可能性があります。
自分でメモリ制限を変更する前に、WordPressホスティングサービスプロバイダーに相談することを強くお勧めします。サイト固有のニーズを分析し、必要であれば安全かつ適切なメモリ制限の増加についてアドバイスしてくれます。
詳しくは、WordPressサポートへの適切な依頼方法に関する投稿をご覧ください。
4.マルチサイト・ネットワークを利用している。
WordPressでプラグインメニューが表示されないもう一つの理由は、あなたのサイトがWordPressのマルチサイトネットワークの一部である場合です。
WordPressマルチサイトネットワークは、WordPressの個別インストールから複数のサイトを管理することができます。これは、同じようなサイトのネットワークを運営する必要がある場合に便利です。
しかし、マルチサイトネットワークと一般的なWordPressインストールの主な違いは、ネットワーク管理者が個々のサイトをよりコントロールできることです。
場合によっては、ネットワーク管理者は、すべてのサイトの一貫性を維持したり、安定性を確保するために、ネットワーク内の個々のサイトのプラグインメニューを無効化することがあります。
この問題を解決するには、ネットワーク管理者にプラグインのインストールを依頼すればよい。
このトピックについては、WordPressマルチサイトインストールですべてのプラグインが表示されない理由についてのガイドを参照してください。
5.間違ったプラグインファイルをアップロードした。
サードパーティのプラグインファイルをアップロードしたいのに、WordPressが以下のようなエラーメッセージを表示し続けるとします：
この場合、そもそも正しいファイルをアップロードしているかどうかを確認する必要があります。プラグインファイルは通常.zipパッケージに入っており、.zip形式を使用します。
また、ダウンロードしたZIPコンテンツファイルに互換性があるかどうかも確認してください。すべてのサードパーティプラグインが信頼できるソースから提供されているわけではなく、これが正しくアップロードされない原因かもしれません。
プラグインのインストールについて詳しくは、以下のガイドをご覧ください：
- WordPressプラグインのインストール方法（ステップバイステップ）
- 初心者ガイド：最適なWordPressプラグインの選び方
- WordPressのバージョンでテストされていないプラグインをインストールすべきか？
また、セキュリティリスクを最小限に抑えるために、WordPress.orgプラグインディレクトリのような信頼できるソースからのみプラグインをインストールすることをお勧めします。WordPress.orgディレクトリには審査プロセスがあり、信頼できる開発者のプラグインを提供する傾向があります。
安全なプラグインを選ぶためのヒントをいくつか紹介しよう：
- 開発が有効化され、ユーザーの評価が高いプラグインを探しましょう。
- プラグインがWordPressのバージョンと互換性があることを確認するために、「最終更新日」をチェックしてください。
- プラグインの説明やレビューを読んで、その機能や潜在的な互換性の問題を理解しましょう。
WordPressのよくあるエラーの修正方法
WordPressにプラグインをインストールできないだけでなく、時々他のタイプの問題に出くわすかもしれません。これらのよくある問題を解決するために、以下の記事をチェックしてください：
- パスワードをお忘れですか？WordPressでパスワードを紛失した場合の復旧方法
- WordPressで削除されたページを復元する方法
- WordPressテーマをアンインストールして削除する方法（ステップバイステップ）
- WordPressのアンインストールと再インストールの方法（初心者向けステップバイステップ）
WordPressでプラグインの追加やインストールができない原因について、この記事がお役に立てれば幸いです。WordPressエラーのトラブルシューティングの初心者向けガイドや、WordPressでよくある画像の問題を解決する方法についての記事もご覧ください。
If you liked this article, then please subscribe to our YouTube Channel for WordPress video tutorials. You can also find us on Twitter and Facebook.
Evan Cleary
I set up a Wordpress site in 2014 and was able to get plugins without going into a business plan. And I sent up another site a few years ago and it was also not any problem to add plugins. As far as I know, it was via Wordpress.com and not Wordpress.org – I downloaded a theme and editors that and used my own URL hosted by a hosting company. I’m quite confused now as no one seems to be saying that this policy of having to pay for a business plan is a new thing. Is it a new thing?
WPBeginner Support
If your site is on a hosting provider and not the WordPress.com website then it is a WordPress.org site. Having to purchase the business plan on WordPress.com for access to plugins is not something new.
管理者
karan
I had one site of mine that had the issue of no option for adding or updating plugins. For some reason define(‘DISALLOW_FILE_MODS’,true); was in my wp-config file.
Once I deleted that line, my plugin options were restored. It took me a while to find this solution. I hope this helps people find this solution.
WPBeginner Support
Thanks for sharing your recommendation
管理者
Sophorn Chhum
Thanks, man. You’re awesome
Amin
Thank you very much!
naema
Excellent.Great it’s working.Thank you!!!
Heide
Thanks for the good article! I am bit confused, because I am super administrator and can’t install any new plugins. I can activate and deactivate plugins for sites or the whole network. But I don’t have the page for plugin installtion. Do you have any suggestions in this case? Thanks!
WPBeginner Support
If you’re using a multisite like it sounds like you are, you would need to install the plugin in the network admin area rather than on the individual sites.
管理者
anis
when i try to install a pluging it shows the following:
Installation failed: Abort class-pclzip.php : Missing zlib extensions
what should i do
WPBeginner Support
For that error, you would want to first reach out to your hosting provider and they should be able to assist.
管理者
Amy Skea
I can’t download I get this message. I have tried various plugins and get the same.
Thank you
Installation failed: Could not copy file. wp-fastest-cache/wpFastestCache.php
WPBeginner Support
For that specific message, you may want to try the recommendations in our article below:
https://www.wpbeginner.com/beginners-guide/how-to-fix-file-and-folder-permissions-error-in-wordpress/
管理者
santosh
hey i cant upload and install pluginsin my wordpress website.
its shows just the blank page.please help me
WPBeginner Support
If you are only seeing a blank page, you would want to follow the recommendations in our article below:
https://www.wpbeginner.com/wp-tutorials/how-to-fix-the-wordpress-white-screen-of-death
管理者
Amarnath
Hey, I am troubling to install wordpress.
“The MySQL Connection could not be established.”
It is written like this what should I do?
WPBeginner Support
You would want to ensure your username and password in your wp-config file are the correct ones, you may also want to check with your hosting provider’s support if this is a new error and they should be able to assist.
管理者
May
Hey.
How Can I transfer my blog from wordpress.com to wordpress.org to get the benefits of the second one ?
WPBeginner Support
For how to do that, you would want to take a look at our article here:
https://www.wpbeginner.com/wp-tutorials/how-to-properly-move-your-blog-from-wordpress-com-to-wordpress-org/
管理者
Zeeshan
hi!
i am install pulgin but faild.
and ERROR IS
Fatal error: Maximum execution time of 30 seconds exceeded in G:\xampp\htdocs\Ecommrace\wp-includes\Requests\Transport\cURL.php on line 462
WPBeginner Support
For fixing that error you would want to follow the recommendation in our article here: https://www.wpbeginner.com/wp-tutorials/how-to-fix-fatal-error-maximum-execution-time-exceeded-in-wordpress/
管理者
Ale Sants
Hello! Same problem here. Cannot ADD plugins.
More details of my site:
WordPress 5.2.2 running Bridge theme, so Wordpress.org. no .com
Hostgator for hosting
I am an admin and no one else has ever done any work on the site, so I am the only admin for sure.
Please help and thanks in advance!
WPBeginner Support
You may want to check with your hosting provider to ensure there are no errors on their end that could be part of the problem. You could try checking your folder permissions as well similar to the article here: https://www.wpbeginner.com/beginners-guide/how-to-fix-file-and-folder-permissions-error-in-wordpress/
管理者
Ale Sants
Thanks so much. Will do that and will send any updates.
Rishabh Jain
Hey!
I want to install WP super cache plugin but when I search it in plugin dialog box, on right top corner it shows ‘Not Available’ Why is it so? Is there any problem with my blog. Please help me out…
WPBeginner Support
Is your site on WordPress.com or a managed hosting provider?
管理者
Mazie
Don’t know what I’m doing wrong with new wordpress.com blog (true newbie). My menu doesn’t look like those above. All I see are the following 7 options, all are listed on the left: Site Identity, Colors & Backgrounds, Fonts, Header Image, Menus, CSS and Widgets. I guess my question is, is this as it should be for the free (.com) site? Is it from this menu that I will create and complete my free blog?
Sorry to be so ignorant about this. I think I’m missing something as I don’t imagine it’s supposed to seem so confusing.
Thank you!
Mazie
WPBeginner Support
Sadly, our tutorials are for WordPress.org rather than WordPress.com which is what you’re using would be part of the confusion. If you go to the wp-admin area of your WordPress.com site the admin area will look similar but you will still have the WordPress.com limitations.
管理者
Sasha
Deactivate Wordpress Plugin: WP Editor and you will be able to see list of your hidden plugin. WP Editor not tested/comparable with new WP version and php 7.
WPBeginner Support
Thanks for sharing what worked for you
管理者
chris
I am trying to install a plug-in on a website that a company designed for me but I don’t have the plugin option in my administrator menu (made sure I was an admin not just a editor). My admin bar is also Red with “PRODUCTION SERVER” next to my name. Are these too related? How to I add plug-ins if I don’t have the the plug-in tab?
Nalin Puri
I am using InstantWP Named automated wordpress local server.If i buy my hosting service can i shift my blog from instant vp to that hosting server of GoDaddy
WPBeginner Support
Hi Nalin,
Yes it can be.
管理者
sajilesh kurup
Hi,
on wordpress website i am able to see pulgin menu, however as i hover mouse pointer over it not displaying option menu of add new
anh tuan
please help me! i’m a admin on my website but i can’t see any plugins on plugin dashboard, in my hostin, it still no problem??
WPBeginner Support
Hello,
You may not have an admin account or someone you hired to work on your website has disabled your access to plugins area. Sometimes developers do this to make sure that their customers don’t accidentally break their websites.
管理者
kevin shiu
How do I go about fixing this myself assuming the original developer is no longer around?
Judy Adams
I tried adding the plug in contact form 7 add-on now I get a white a screen after activating or trying to activate. I cannot go to my dashboard or anything in word press now. When trying to FTP in to deactivate plugin I am not sure what login and password to use. Can you please help me? I don’t want to lose my whole website I created because I cant get in now.
Riazvic
Hi,
I am having an e-commerce website, unfortunately, I am having a theme which came with a premium plugin which I have purchased. their plugin section is available but widget section is not available how can I put google translate code into that theme where should use that code in the theme files?
I hope to get an answer here.
thanks in advance for your support.
Kamal
David
Hello.I have the same issue of can not add new plugin in wordpress plugin panel.
1. No “add new” plugin options
2.No “trash” plugin options
3.Other issue is I can not find the “editor” in appearance panel
Would you like to let me know how can i fix this?
Rizqi
I have same issues, it also can’t update existing plugins, because the link is gone. Have got the solutions?
Jacqueline
Hi. I purchased the Divi theme and plug in file. The theme uploaded fine but when I go to upload the plug in file it fails. Anything I can do? Thank you for your support on this matter.
WPBeginner Support
Hi Jacqueline,
You can try installing plugin via FTP.
管理者
Aziz Nazarov
Hello,
Thank you for sharing such a valuable info.
Maybe this’s a bit off topic question.
I’m having a small issue at the moment with adding a new submenu page.
So basically I got an Astra Theme (not a pro version) with Beaver Builder.
I add the page as usual then add to the menu under sub-item, all looks good.
But when I click on the sub menu page it doesn’t take me there. It basically takes me to a home page.
What could be an issue? Could you help me please?
Thank you
Sir Joe
Thanks a lot! Your article helped me
candy
I cannot activated and install my plugin.
Parse error: syntax error, unexpected T_FUNCTION, expecting ‘)’ in E:\AppServ\www\shopify\wp-content\plugins\ninja-fb-private-reply\src\Facebook\autoload.php on line 45
please help me fix this .
Mark
Hi, I cant log on to my wordpress account. It says “ERROR: There is no user registered with that email address.” I know for a fact that that is the correct email address associated with the account.. Please help!!! I dont have any of the other information required to reset the account (such as transaction ID) HELP!!!!
mark
should I switch to wix or weebly? this is stupid. I have to sit here for hours googling to not be able to do the stupidest simplest things. I don’t want to learn wordpress I just want a simple ecommerce site that wont be like a college course to get set up.
M
lokesh
I’m getting this message while installing the plugins.
An unexpected error occurred. Something may be wrong with WordPress.org or this server’s configuration. If you continue to have problems, please try the support forums.
How to solve please help
Yeboah Martin
I had this message when trying to upload a plugin:
POST Content-Length of 11688443 bytes exceeds the limit of 8388608 bytes in Unknown on line 0
WPBeginner Support
Hi Yeboah,
You need to increase the maximum file upload size.
管理者
Tabish
Hi! Wanted to ask you guyz two things: You guyz run this website on WordPress, right? Which theme do you use? And like YEBOAH MARTIN said, I was facing the same error when I tried to create a video streaming site and uploaded videos. I did increase the file size limit to 977 GB! And I am sure that it isn’t the storage, as my hosting provider has made unlimited disk storage available! (Cuz I created that hosting service!)
WPBeginner Support
Hey Tabish,
We use a custom made WordPress theme. As for videos, please see our guide on why you should never upload videos to WordPress.
Jitendra Mahato
Hi,
I have migrated my blog yesterday. All the things are good but the error in the plugin. I have deleted all the plugins. After then, while i am starting to install the plugin, then No, any plugin is adding..
While adding….
Messages lke this…
Could not create directory. /home/danfeh5/public_html/example.com/wp-content/plugins/boombox-theme-extensions
WPBeginner Support
Hey Jitendra,
It seems like your WordPress directory permissions are incorrect. Please see our guide on how to fix file and folder permissions error in WordPress
管理者
Angelo
Hi.Why is it my comment section is closed?Even if i downloaded comment plugin it seems nothing changed
WPBeginner Support
Hi Angelo,
If comments are closed on all your articles, then go to Settings » Discussion page inside WordPress admin area and check the box next to ‘Allow people to post comments on new articles’ option. Any new article you now add will have comments enabled by default.
For your older article you will have to edit them and then on the post edit screen click on the Screen Options button at the top right corner of the screen. Check the box next to Discussion option. Now scroll down below the post editing area and you will see a Discussion meta box where you need to check the option ‘Allow Comment’ option.
管理者
Lisa
Hi I got this when trying to install jetpack and its not on my list of plugins and I am not sure what to do Installing Plugin from uploaded file: jetpack.4.9.zip
Unpacking the package…
Installing the plugin…
Destination folder already exists. /home/content/p3pnexwpnas02_data01/46/2075146/html/wp-content/plugins/jetpack/
Plugin install failed.
Return to Plugin Installer
WPBeginner Support
Hey Lisa,
Your website already has a folder called jetpack. You need to connect to your website using an FTP client or File manager in Cpanel and delete that folder to install the plugin from the zip file.
管理者
Omar
Hi, I can see and add plugins in “my” installation (its not a multisite) of wordpress but suddenly there’s no option for activate/delete under the plugin name, but I still can do this trough the bulk actions option… did someone know why this happens?
Omprakash
Hi Why none of WP Plugins are installing in my WP Dashboard please Help me
Rafael
I was added as ‘admin’ in a multisite WordPress so I couldn’t see the Plugins. Asked for the ‘network admin’ to enable Plugins in ‘Network Configurations’ but looks like that just allows me to see the Plugins, still not able to install new plugins.
WPBeginner Support
Hey Rafael,
The network admin or super admin can allow individual site admins to activate or deactivate plugins on their own.
管理者
Rafael
Thank you for the reply, I got it now. It just wasn’t clear, I see now that only the network admin can install new plugins.
zork
awesome man: define(‘WP_MEMORY_LIMIT’, ’64M’);
this solved my problem after a migration from local to production
thank you so much!
Ankur Sharma
i have installed wordpress on pc with xampp. when i install ULTIMATE MEMBER plugin it shows an error and when i upload the plugin it shows the memory limit problem..
i have already added that line you mentioned i.e.
define(‘WP_MEMORY_LIMIT’, ’64M’);
and also i have changed a line in php.ini file in xampp
; Maximum allowed size for uploaded files.
upload_max_filesize=3000M
nothing is working .. please help me ..
Thanks!!
tom bukkots
Can’t add or delete plugins in WordPress
Nicole
I have wordpress.com/wp-admin.. I have admin rights and i still have no options for adding new plugins. Any suggestions?
WPBeginner Support
Please see our guide on the difference between self hosted WordPress.org vs free WordPress.com blog.
管理者
Ali Shair
if i Host my wordpress.com site on Hostgator or go daddy then it is possible to upload themes or plugins
WPBeginner Support
Hi Ali,
No you cannot host your WordPress.com site anywhere else. You will need to use self hosted WordPress.org.
管理者
Betina
Hi,
If I buy a domain from wordpress.COM will it let me download and install plugins like adsense?
Thanks!
WPBeginner Support
No it will not. You will also be unable to use Adsense. Please see our guide on the difference between self hosted WordPress.org vs free WordPress.com blog.
管理者
Tim McCoy
I get the following message when I try to download any plugins:
Downloading install package from ….
Download failed. Could not open handle for fopen() to /home/content/95/9132095/tmp/seo-wizard-BrHIzr.tmp
WPBeginner Support
This error could occur due to incorrect file permissions.
管理者
Leah
I was sure I had a wordpress.com site, but I have access to plugins like Jetpack and Discuz. Has this changed since this article was published, or do I have Wordpress.org?
Nadya
I am trying to get rid of dates on my wordpress blog but everywhere I look seems to be suggesting downloading a plug-in but from your post we are not able to install plug-ins…. So does this mean we are not able to delete dates in regular wordpress.com?
WPBeginner Support
Please see our guide on the difference between self hosted WordPress.org vs free WordPress.com blog.
管理者
ahmad
hi i have this warning when i want to install plugin or them that is happended to me when i moved wordpress from loaclhost to livesite
Downloading install package from
Warning: unlink(/home/fanousmd/public_html//home/fanousmd/public_html/tmp/contact-form-builder.1.0.39-iYKOjV.tmp): No such file or directory in /home/fanousmd/public_html/wp-admin/includes/file.php on line 481
Download failed. Destination directory for file streaming does not exist or is not writable.
Return to Plugin Installer
Denise
Is there a way to add a booking calendar to a wordpress.com site considering it does not take plugins. Is there a non-plugin option? What are the options other than switching?
Mattie
I have managed to solve my problem by deleting the entire MYSQL database and starting over from scratch.
Josh
what if I use xampp for local hosting? can this work to add plugins?
WPBeginner Support
Yes please check our guide on how to install WordPress on your computer using Wamp. However, the site on your local server will be only visible to you.
管理者
Joey Ayoub
This really ruins the WordPress experience for me. All I wanted was to be able to write my own meta descriptions and now I’m told I have to pay even more to do just that? For goodness’ sake.
WPBeginner Support
if you are using WordPress.com, then yes you can not install plugins or modify themes on your own. However, using a self-hosted WordPress site you can make all these changes using free plugins and themes.
管理者
Ryan Naylor
I was having this problem yesterday. I wanted to install the Gravity Forms Directory plugin, which I did and activated. Yet, I couldn’t find it within my dashboard and even following the plugin directions, was not able to follow. My only conclusion is that I need to actually purchase Gravity Form in order to install and use the G.F. directory plugin.?
Editorial Staff
Yes, you have to purchase GF first.
管理者
Ignacio
One more (happened to me today):
I forgot that I wrote this on wp-config:
define(‘DISALLOW_FILE_MODS’,true);
That will disable plugins install, updates…
FourteenG
I had one site of mine that had the issue of no option for adding or updating plugins. For some reason define(‘DISALLOW_FILE_MODS’,true); was in my wp-config file.
Once I deleted that line, my plugin options were restored. It took me a while to find this solution. I hope this helps people find this solution.