9 Reasons Why You Can’t Install WordPress Plugins

Published at wordpress plugin management by Jacek Piotrowski on 26th Mar 2021

One of the things that make WordPress so popular is its customizability. Thanks to hundreds of plugins available, you can add almost any feature there's to your site. All that without the need to code or hire an expensive developer.

Unfortunately, sooner or later, many beginners (and experienced website owners alike!) have to ask themselves the same question:

'Why can't I install Plugins on WordPress?'

Sometimes, especially new WP users, face a situation where they can’t install any plugin at all. Other times, it's just one particular plugin that they really want to install yet can't get to work.

This is especially frustrating if that one plugin is all you need to finish all your work on the site. Or when it's a feature that's absolutely essential to your website. '

But, before we get to the solutions, let's take a quick look at how to upload and install WordPress plugins the right way.

Installing a WordPress plugin (on a self-hosted site)

Installing a WordPress plugin (on a self-hosted site)
Uploading WP plugins is very straightforward. Simply click the Plugins tab in the menu and hit Add New. Then, click the Upload Plugin button:

Upload WP Plugin

Then, you want to either select Choose File button or simply drag-and-drop the plugin's .zip file:

Uploading a Plugin

If the installation succeeds, you'll see the following note. Simply click the blue button to activate the plugin:

Successful Installation WP Plugin

Unfortunately, sometimes, the process won't go that smooth. That's when you'll encounter one of the common WordPress plugin installation errors.

Thankfully, from our experience, 99% of the problems come down to one of the below:

1. You're using WordPress.com and your plan doesn't allow it.

The bulk of the article covers issues related to the self-hosted WordPress installation. But, we can't forget about its cloud-hosted cousin. Now, there are two things you need to keep in mind:

First, WordPress.com is a separate platform from WordPress.org. The latter allows you to build a WordPress-based website on your own server. WordPress.com is a closed environment, where you pay a monthly fee for your website.

The big downside is, you have very little freedom. In fact, you're essentially tied to their hosting and pricing plans. The upside is, you don't have to worry about things like hosting. However, if you want to install plugins, you have to buy either their business or eCommerce plan.

Wordpress Plugins

And, if you try to install plugins on a cheaper plan, all you'll see is the below:

WPcom Plugin Installation

What's more, you can only select plugins that are available in the repository. You're not allowed to upload any external plugins.

Solution: There are two things you can do. First, you can buy their Business or eCommerce plan. Alternatively, you can migrate to a self-hosted WordPress site. With tools like WP Blazer's WordPress Install, you can deploy new sites in no time. And, thanks to its other features, you'll be able to manage your site easier than ever before!

2. You don't have the right permissions.

To upload and install plugins, you need to have the right permissions. If you're the owner, and the only user of the site, you can skip this point. As your WP user becomes an administrator by default, you should be able to install plugins.

But, if you’re not an administrator, the easiest way to tell if you can install plugins is to look at the sidebar. If it looks something like the below (no Plugins menu), you don't have the right permissions.

No Permission to Install

The permissions issue is especially common for people who don’t own the site and were invited to help manage it. For example, writers or brand-new website administrators.

Solution: Ask the website administrator to change the permissions associated with your user profile.

3. You're exceeding the PHP memory limit.

The next issue is easy to spot, as WordPress will tell you specifically that it needs more memory. This is especially common on brand new sites with little technical optimization

Usually, the error will say something like the following:

Fatal error: Allowed memory size of 67108864 bytes exhausted

Of course, the numbers might differ. Nevertheless, the error indicates you need to increase your PHP memory limit.

Solution: There are two places where you can change your memory limits. The first one is your WordPress installation. The second is the server that you host your site on itself. Ideally, you should set them both to at least 512 MB.

Let's start with checking your WordPress memory limit size. To do that, head over to Tools > Site Health:

Site Health Menu

Then, you want to scroll down to server:

PHP Memory Size Limit

If this number is below anything you've seen, you need to increase it. To turn bytes into megabytes, use this free bytes to megabytes converter.

The quickest fix is to edit your wp-config.php file and add the WP_MEMORY_LIMIT limit. Just make sure that you do that before the "Happy blogging" bit:

define( 'WP_MEMORY_LIMIT', '512M' );

If that won't work, you may need to check with your hosting provider who may be able to assist you. Keep in mind that, if you're on a very low-end setup, you may also need to upgrade your hosting to access more resources.

Note: For more information on how to edit wp-config.php, scroll down to the bottom of this article.

4. Your website is part of a WordPress multisite network.

So, your PHP is fine and you have all the permissions, yet you're still asking yourself why can't I install plugins on WordPress? The multisite might be where it's at.

Now, this issue happens only if you own more than one site, and use the WordPress multisite installation to manage them. If you didn't deploy your site as part of a multisite (what's possible even with a single site), you can skip this point.

But, if you own a multisite network or you're unsure - here's how to install plugins on a WP multisite.

The easiest way to tell that you're on a multisite is to look at the name of your site. If, instead of just the name of your site you'll see the "My Sites" menu, you're on a multisite:

Multisite Indicator

Another way to do that is to look at your plugins menu. If you know you have the right permissions yet there's no Add New option in the plugins menu - you're on a multisite:

No Add Plugins Menu

Of course, that doesn't mean you can't install plugins on a multisite - you just do it slightly differently!

Solution: In order to install plugins on a multisite, you need to go to Network Admin. There, you need to find a separate Plugins menu where you'll also have the option to add a new plugin.

Network Admin Plugin Installation

Keep in mind that when you Network Activate a plugin, it becomes active on all sites in that network. This means you’ll only be able to deactivate it in the Network Plugins menu:

Network Active Plugin

5. You're uploading a .rar archive (or any archive that's not a .zip file).

To install a WordPress plugin, you need to upload its files to your website. That's unless you're installing one from the WordPress repository. If that's the case, you can skip this step.

Plugin Installation Zip Upload

If you try to upload a .rar or any other archive, you'll get the following error:

Plugin RAR Installation

Solution: Double-check if your plugin's archive extension is .zip. If you can't see the extension, you can enable it in view settings (Windows 10):

View File Extensions

If it's a different archive, you'll need to unpack it and then add it to a .zip archive. To do that you can use a tool like 7-Zip (free & open-source).

6. Plugin files in your archive are inside another folder.

The next one is another common reason why you may be forced to wonder "Why can't I install Plugins on WordPress?"

Sometimes you will get a seemingly good .zip file that you'll still be unable to upload correctly:

Plugin Zip Folder Error

If that's the case, it's worth checking if plugin files are on the correct level in the archive.

You see, the correct path for plugin files is:


If the structure looks anything like the above, it could be causing the error. The most common mistake that we see is a plugin packed into a plugin-folder twice:


Usually, this happens when someone unpacks the files to a new folder and then packs the whole folder.

Solution: Unpack the archive and pack just the main folder with the plugin files. If you need a tool to do that, see #5.

7. Some of the files are missing

Another reason that you might be seeing the same error is when core plugin files go missing:

Plugin Installation Failed No Files

Unfortunately, WordPress won’t tell you which files are missing. It won't even indicate whether it’s one file or half the archive that's gone.

Solution: Trying to find the missing files manually could be too time-consuming. In most cases, it could be outright impossible - especially if you're not a developer.

The fastest way to solve this is to find another source of the plugin and see if their version fails too. If it does, you might have to reach out to the plugin's developer or support.

8. Your plugin files are corrupt.

Sometimes, the plugin will upload just fine yet it still won't activate. Instead, you'll get a "syntax error" or a "parse error":

Plugin Activation Syntax Error

If that’s the case, then, in theory, all files are there. But, there’s an error in the code itself that makes it impossible for the plugin to activate..

Solution: Most of the time, you'll have to reinstall the plugin. Sometimes, the issue will be so small (and common), that you'll be able to fix it yourself by editing the file in a text editor.

Especially that, in theory, WordPress points you to where the error is. However, if you're not a developer, most of the time it's better to reach out to the plugin's creator or customer support.

9. Someone has hacked your website.

This may sound like an “it cannot possibly happen to me” thing. Yet, it’s not as unusual as you’d think! Especially if you didn’t secure your website in any way. Or, if the hacker somehow got their hands on your username and password.

If you get hacked, there's plenty of ways in which the hacker could damage the site. They could remove some files or add unwanted code to them. They could even block you from managing your own site.

For example, it's possible to cancel your permission to make changes to your site. In this case, won't be able to install or delete plugins even if you're an administrator!

To do that, all the hacker has to do is edit the following lines in the code:

define(‘DISALLOW_FILE_EDIT’, false);
define(‘DISALLOW_FILE_MODS’, false);

And change them to the following:

define(‘DISALLOW_FILE_EDIT’, true);
define(‘DISALLOW_FILE_MODS’, true);

Solution: To solve this, you need to access your website's files and look for the above lines in the wp-config.php file. To access the editor, you need to set them both back to "false".

define(‘DISALLOW_FILE_EDIT’, false);
define(‘DISALLOW_FILE_MODS’, false);

BONUS: Accessing your website using an FTP file manager

While some of the files can be edited directly in the WordPress editor, core WP files require you to access FTP.

To do that, you want to use a free FTP manager like FileZilla. In the following example, we'll be editing the wp-config.php file to increase the WP memory limit.

First, you'll need to connect Filezilla to your server. To do that, hit File > Site Manager and add your site:

FTP Login Password

You'll need a server IP address, as well as your FTP user and password. If you don't have them, reach out to your host. If you have them, enter them in their respective fields and click connect.

Next, you'll see a list of files on your server. Find and open folder public_html:

Server 1 Public HTML

Next, find wp-config.php - the file should be in the root folder. Right-click on it and hit View/Edit.

File Edit Filezilla

If you've never used FileZilla before, you'll be asked to associate a program with the selected filetype. We recommend that you try a very handy (and free) text editor, Notepad++, which makes managing the code a breeze. Once you install it, select custom program and navigate to its folder to select it:

Notepad Plus

Next, you want to scroll down to the bottom of the file, right before the "Happy blogging" bit. Once there, add the following line to increase your site's memory limit:

define( 'WP_MEMORY_LIMIT', '512M' );
PHP Limit Notepad

Of course, increasing your memory limit is just an example to help you install your plugins. There's plenty more that you can do editing that file. But, that's a topic for another article!

You could also make WordPress plugin management even easier!

Encountering any of the above errors when working on your site can be really frustrating. Especially if you are in a hurry and don't feel like asking yourself "Why can't I install Plugins on WordPress?" for the hundredth time. But, that's where WP Blazer can help you.

Its theme and plugin management capabilities can help you streamline the whole process. Of course, it won't prevent all the errors you could face when uploading and installing plugins.

After all, it can’t fix the plugin files for you. But, it can save you plenty of time that you can use to do what you want the most – to grow your website and online business. To start managing your WordPress plugins with ease, start your free trial here.