IIS7: A process serving application pool 'YYYYY' suffered a fatal communication error with the Windows Process Activation Service

Question

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...

Fascinator

@ScottE Link is dead – Conaway

Updated link: mvolo.com/… – Chinkapin

In my case, problem was an unlimited recursive loop in my application code. – Taluk

I know the post is old, but I've got to say that when I was searching for a solution to my problem, it didn't help. I must say that my problem was related to database users. They didn't have EXECUTION permissions. C-ya. – Algid

Answer 1

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.

IIS Application Pool Crash and Debug Diag

Distance

For further information, here's a TechNet blog article showing how to configure the DebugDiag tool to catch a crash dump: blogs.msdn.microsoft.com/parvez/2016/08/06/… – Archaeornis

Highly recommend this soluition. In our case it turned out to be a recursive method. – Treadway

Answer 2

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.

Aleron

Mine was missing nuget packages (System.Net.Primitives in my case) – Neeley

In my case, problem was an unlimited recursive loop in my application code. – Taluk

I had numerous missing files and a wrong build of some type. Something wrong with my deploy setup. – Freighter

In my case, problem was 'ApplicationPoolIdentity' that did not have read permissions. see: #7334716 – Latitudinarian

For me it was URL Rewrites and Application Request Routing not recognized by IIS. – Reverberation

It worked, it didn't show an explicit error but the last working operation was an access to %systemroot% that failed – Mcgraw

Answer 3

Make sure that each Application Pool in IIS, under Advanced Settings has Enable 32 bit Applications set to True

Polluted

Could you please explain why this would solve the OP's issue? I am asking because I and encountered the same issue on 64-bit Windows Server 2008 R2 and would like to know if this solution can be generalized to my case. Thank you! – Doubletime

Same answer given here https://mcmap.net/q/672131/-how-to-diagnose-iis-fatal-communication-error-problem, so seems to be something to it. Didn't work for me unfortunately. – Almeida

I recently ran into this issue with an ODBC connected product moved to a new server. Flipping the Enable 32-Bit Application to true solved the issue. – Thermostatics

what if i do not want 32-bit apps on the AppPool, and really need 64-Bit? what is the solution for "Run only 64-Bit" scenarios? – Lamonicalamont

Had the same issue. But this is weird. I switch that setting to true, apply the change, and then, go back and put it to false again and guess what, it is still working... I'm mystify by this... – Bertrando

This is a red herring, not a solution to the problem. The problem is whatever is causing the application to fail. – Deoxygenate

For me the windows logs showed a problem with virtual memory of the process which could not be increased. I think that setting "Enable 32Bits Application" limits the size of the process at 2GB and simply forces a pool recycle when the limit is reached. You can also set the a virtual memory limit in the advanced parameters of the application pool. – Misspeak

Downvoting. Stan is right: "The problem is whatever is causing the application to fail." This workaround will cause you some serious headaches if you require the app pool to run 64 bit. – Hailstorm

Answer 4

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.

Microspore

Answer 5

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.

Nuclei

Answer 6

For me the problem was a configuration file that was missing an Element.

Treen

Answer 7

In our case, the issue was related to using of app.UseCors(corsOptions) in Configuration(IAppBuilder app) method. The issue also was accompanied by increase in IIS response times and spike of 502 errors. We don't know how exactly it caused the issue though.

Viva