Hi,

After the update from 8.1 upgrade 2 to 8.1 upgrade 4, there have been issues with the WebNavigator IIS pool, which periodically crashes and errors:
Warning 10/3/2025 12:13:36 PM Microsoft-Windows-WAS 5013 None A process serving application pool 'WebNavigatorAppPool' exceeded time limits during shut down. The process id was '23788'.
Information 10/3/2025 12:12:06 PM Microsoft-Windows-WAS 5186 None A worker process with process id of '23788' serving application pool 'WebNavigatorAppPool' was shutdown due to inactivity. Application Pool timeout configuration was set to 20 minutes. A new worker process will be started when needed.
Information 10/3/2025 10:42:45 AM Microsoft-Windows-WAS 5186 None A worker process with process id of '11692' serving application pool 'WebNavigatorAppPool' was shutdown due to inactivity. Application Pool timeout configuration was set to 20 minutes. A new worker process will be started when needed.
Warning 10/3/2025 10:17:53 AM Microsoft-Windows-WAS 5011 None A process serving application pool 'WebNavigatorAppPool' suffered a fatal communication error with the Windows Process Activation Service. The process id was '3736'. The data field contains the error number.
Information 10/2/2025 3:38:56 PM Microsoft-Windows-WAS 5082 None A worker process with pid '3736' that serves application pool 'WebNavigatorAppPool' has been determined to be unhealthy (see previous event log message), but because a debugger is attached to it, the Windows Process Activation Service will ignore the error.

Additionally, an error window constantly pops up with the following message:

Faulting application name: w3wp.exe, version: 10.0.20348.1, time stamp: 0x7feb3edd
Faulting module name: ntdll.dll, version: 10.0.20348.3932, time stamp: 0xdc3ed3bb
Exception code: 0xc0000374
Fault offset: 0x000e93c9
Faulting process id: 0x4614
Faulting application start time: 0x01dc39a7e0d394c9
Faulting application path: C:\Windows\SysWOW64\inetsrv\w3wp.exe
Faulting module path: C:\Windows\SYSTEM32\ntdll.dll
Report Id: debff23b-101d-4af1-bf56-d5aeff02f805
Faulting package full name: 
Faulting package-relative application ID: 

[Log attached]

Hi,

open IIS and delete the WebNavigator site

Then open WinCC Web Configuration Center and create a new one to check if the site was damaged.

I deleted the pool and the site and created them again by webconfigurator, but the error still remains

You migrated / converted all screens and scrips in WinCC Explorer?

also published the screens?

if yes, then you should create some support request, Siemens SiePortal

Migrated from 7.4 to 8.1 simply by opening the project in the new version, since the Project Migrator Tool says that the project does not require migration.

Hi,

thanks for the advice,

 project migrtated successfully, but webnavigatorapp pool still crashing