Website example.com is not accessible. The following error is shown in a browser:
504 Gateway Time-out
The following error message appears in the domain error log file at Domains > example.com > Logs:
[proxy_fcgi:error] [pid 42290:tid 140458047010560] (70007)The timeout specified has expired: [client 203.0.113.2:54693] AH01075: Error dispatching request to :, referer: http://example.com/gallery
In Plesk > Domains > example.com > PHP Settings it is shown that the website uses "FastCGI application" (and not "FPM application") PHP handler.
Execution PHP code of the website takes longer than the specified timeout.
To fix the issue increase the timeout. FastCGI limits can be increased for an affected domain only or on a server-wide level. Both ways are described below.
Note: In case it is necessary to run only one script with the increased timeout, consider running it in a scheduled task: How to schedule a task in Plesk for Linux?