Symptoms

1. example.com website is not available with the error below:

500 Internal Server Error
C:\Parallels\Plesk\Additional\PleskPHP5\php-cgi.exe - The FastCGI process exited unexpectedly

2. The following error can be found in the Even Viewer:

Faulting application name: php-cgi.exe, version: 5.2.17.17, time stamp: 0x4d25fc25
Faulting module name: ntdll.dll, version: 6.1.7601.17514, time stamp: 0x4ce7ba58
Exception code: 0xc0000005
Fault offset: 0x00042092
Faulting process id: 0x4550
Faulting application start time: 0x01d2945ec1adafde
Faulting application path: C:\Parallels\Plesk\Additional\PleskPHP5\php-cgi.exe
Faulting module path: C:\Windows\SysWOW64\ntdll.dll
Report Id: 08320fbd-0052-11e7-b831-00ffd710dc08

3. A lot of domains are assigned to the same application pool.

Cause

Too many domains assigned to one application pool.

Resolution

Create dedicated application pool for the domain:

1. Go to the Plesk > Domains > example.com > Dedicated IIS Application Pool for Website.

2. Press Enable.