This error message usually indicates that the server cannot write to the specified directory. In this case, the directory in question is “wp-content/uploads.”

How can you fix this permission issue?

To fix this error, you must ensure that the server has the correct permissions to write to this directory.
One way to do this is to change the directory’s permissions to 755 or 777 using your FTP client or the file manager in your hosting control panel. You can also try changing the ownership of the directory to the user that the web server runs as (e.g., “www-data” or “apache”).

Other scenarios to check for:

In my case, I had WordPress installed in a subdirectory. Example: https://www.domain.com/blog. The folder blog was a virtual directory to which the application pool user did not have write access.

I exhausted all the options above and could only fix this issue once I checked the different users’ permissions. Then, I noticed the application pool group account did not have written permission. Once updated, the error was gone and then I was able to upload images and update the plugins as expected.

If you are still having trouble after trying these steps, the issue may be caused by a plugin, theme conflict, or a problem with your WordPress installation. You may consult your hosting provider or a WordPress developer for further assistance.