We're running a 32-bit Windows server 2008 with an IIS version of 7.
We're attempting to publish an asp.net 4.0 webapp and so far our attempts have only yielded a few warnings in the serverlog without even stopping the 4.0 application pool
A process serving application pool 'ASP.NET v4.0' suffered a fatal communication error with the Windows Process Activation Service. The process id was '1904'. The data field contains the error number.
The application is running under a 4.0 app-pool and under the default website.
We've also got some older .asp's running flawlessly.
Even when attempting to publish a barren (read. only 1 line of text) .aspx-file it failed miserably... We've since long run out of ideas on what to do so any form of input would be appreciated...
Make sure that each Application Pool in IIS, under Advanced Settings has Enable 32 bit Applications set to True
I was debugging the problem for the better part of the day and when I was close to burning the building I discovered the Process Monitor tool from Sysinternals.
Set it to monitor w3wp.exe and check last events before it exits after you fire a request in the browser. Hope that helps further readers.
Debug Diagnostics Tool (DebugDiag) can be a lifesaver. It creates and analyze IIS crash dumps. I figured out my crash in minutes once I saw the call stack. https://support.microsoft.com/en-us/kb/919789
When I had this problem, I installed 'Remote Tools for Visual Studio 2015' from MSDN. I attached my local VS to the server to debug.
I appreciate that some folks may not have the ability to either install on or access other servers, but I thought I'd throw it out there as an option.
I ran into this recently. Our organization restricts the accounts that run application pools to a select list of servers in Active Directory. I found that I had not added one of the machines hosting the application to the "Log On To" list for the account in AD.
来源：https://stackoverflow.com/questions/7204444/iis7-a-process-serving-application-pool-yyyyy-suffered-a-fatal-communication