Joomla 4.4.x (also worth checking on Joomla 5.x)

When installing or updating an extension, Joomla displays the message:

Install path does not exist.

However, the actual cause is that PHP cannot write extracted files because the user's filesystem quota has been exceeded.

The Apache/PHP error log clearly reports:

file_put_contents(): Write failed with errno=122 Disk quota exceeded

The installer continues and finally reports "Install path does not exist", which is misleading and makes troubleshooting unnecessarily difficult.

Steps to reproduce

Configure a hosting account with a small filesystem quota.
Fill the quota until only a few KB remain.
Install or update any Joomla extension.
The installer starts extracting the package.

Error Install path does not exist.

Joomla should detect the failed write operation and display a more helpful error, for example:

Unable to write extracted files.
The filesystem is full or the user's disk quota has been exceeded.
Please check available disk space and user quota.

or at least include the original filesystem error returned by PHP.

Additional information

The PHP error log already contains the correct error (Disk quota exceeded). The Joomla installer hides this information and replaces it with a generic message that points administrators in the wrong direction.