Can't update Joomla or Moodle: file_uploads is set to 'off'

Symptoms

• Can't install a Joomla update with the Plesk APS Catalog or in Domains > example.com > Applications > Joomla

  Error: Unable to install the app on website example.com because hosting settings of this website do not meet the installation requirements. These requirements are listed below. Try installing the application on another website or contact your hosting provider to resolve this issue.​

  Requirements PHP settings
  The PHP parameter file_uploads is set to 'off'. Set it to 'on' to meet the app requirements.
  PHP extension
  The 'json' extension was not found.
  PHP extension
  The 'mysqli' extension was not found.
  PHP extension The 'zlib' extension was not found.
  PHP extension
  The 'xml' extension was not found.

• PHP info shows the wrong information or an error

  Error: Unable to retrieve information about the PHP configuration.

Cause

Rewrite rules are redirecting requests incorrectly, and Plesk is unable to correctly parse PHP requests as a result.

Resolution

Remove the rules temporarily to update the application.

1. Log into Plesk
2. Rename the .htaccess file inside the site's document root in Domains > example.com > File Manager
3. Remove any rewrite rules present in Domains > example.com > Apache & nginx Settings > Additional apache/nginx directives
4. Update the application
5. Revert the changes applied on Step 2