an unhandled win32 exception occurred in w3wp.exe
I get the following exception when trying to load an ASP.NET MVC website:
Unhandled exception at 0x07070a91 in w3wp.exe: 0xC0000005: Access violation reading location 0x00000000.
The Visual Studio Just-In-Time Debugger opens and the only information I can see in the debugger is this:
Call stack location:
msvbvm60.dll!06c00a91()
The website uses some COM objects and everything worked fine until last week. This problem appeared out of the blue.
This is the error log from Windows Event Viewer:
Faulting application name: w3wp.exe, version: 7.5.7601.17514, time stamp: 0x4ce7a5f8
Faulting module name: MSVBVM60.DLL, version: 6.0.98.15, time stamp: 0x4a5bda6c
Exception code: 0xc0000005
Fault offset: 0x00030a91
Faulting process id: 0x1a0
Faulting application start time: 0x01cd31fcb47f66d8
Faulting application path: C:\Windows\SysWOW64\inetsrv\w3wp.exe
Faulting module path: C:\Windows\system32\MSVBVM60.DLL
Report Id: f5db0ae3-9def-11e1-ad79-005056c00008
Do you have any suggestions to help troubleshoot this problem?
Edit: I managed to solve the problem and now everything works. The solution involved tweaking some registry settings that the custom dlls need in order to function properly. So the problem didn't actually appear out of the blue, I just didn't realize some registry values were modified, which caused a com dll to crash.
Answer
Open the Advanced settings dialog of the Application pool that is serving the application in IIS Manager, and set: Enable 32-Bit Applications to True