Issue IIS/ASP.NET/Umbraco exception on on w3wp.exe and pcre.dll

[Aapklub]

I have a Windows Server 2025 VPS managed using Plesk for Windows. On it, I host multiple Umbraco Websites. Since recently, an issue occurs where some sites' application pools appear to crash, taking that specific whole site offline until they are recycled. I can consistently reproduce it by attempting to sign in to the Umbraco backoffice on a site. In (Chromium) browsers, this yields ERR_HTTP2_PROTOCOL_ERROR. The website/Umbraco logs don't show any peculiarity, while the logs in the Windows Event viewer display following error:

Faulting application name: w3wp.exe, version: 10.0.26100.1882, time stamp: 0xc6bd45bd
Faulting module name: pcre.dll, version: 0.0.0.0, time stamp: 0x63b62f6d
Exception code: 0xc00000fd
Fault offset: 0x0000000000013ecf
Faulting process id: 0x1F24
Faulting application start time: 0x1DBEAD3ACB044B9
Faulting application path: c:\windows\system32\inetsrv\w3wp.exe
Faulting module path: C:\WINDOWS\System32\inetsrv\pcre.dll
Report Id: 05530de0-f951-4855-b3e0-b1ece5a4a8fd
Faulting package full name:
Faulting package-relative application ID:

The faulting module appears to be an IIS DLL, which makes sense, as multiple sites display this behaviour, although nothing has changed on the system recently to warrant this.

 

[Sebahat.hadzhi]

@Aapklub , maybe this can help debugging the issue:

How to debug w3wp clr.dll error

My client has an ASP.NET application installed on two production servers (balanced with NLB, but that's irrelevant). Both servers crash every 3-4 hours with the following event viewer logged error:

stackoverflow.com