[SOLVED] Windows 2019 and PHP 7.3: "session_start(): ps_files_cleanup_dir: opendir failed: No such file or directory (2)"

Windows 2019 and PHP 7.3: "session_start(): ps_files_cleanup_dir: opendir failed: No such file or directory (2)"

Having this problem. I know there is similar questions, but none of them provided a solution.

Windows Server 2019 server core
PHP 7.3.7 x64 under IIS.

Error message:

PHP Fatal error: Uncaught ErrorException: session_start(): ps_files_cleanup_dir: opendir(D:\TempPHP) failed: No such file or directory (2).

The directory does exists and it is full of sessions files.
There is FULL permissions (I know, security risk, but I'm first trying to make it work) for the application pool user (IIS AppPool...), IUSR, IIS_IUSRS, LOCAL SERVICE, LOCAL NETWORK, SYSTEM and CREATE OWNER.
The error message seems to shows randomly.

Some relevant php.ini settings:

session.gc_probability = 1
error_log = "D:\TempPHP\PHP73x64_errors.log"
upload_tmp_dir = "D:\TempPHP\upload"
session.save_path = "D:\TempPHP"
sys_temp_dir = "D:\TempPHP"

edit: "D:\" is a local partition. Not a mapped or a shared drive. Logs and sessions are being written successfully. It seems that php just can't remove those files.

Solution

Ok, found out the problem.

Seems like that with windows the session.save_path cannot be in a different disk / partition from the PHP executable path. In my case PHP directory was c:\Program Files\PHP\v7.3, so I moved the TempPHP folder from D: to C: partition and changed the value of session.save_path from "D:\TempPHP" to "C:\TempPHP". Now the sess_xxxxx files are automatically cleaned up and there is no more error messages.

Don't know if this holds true for others php or windows versions.