I'm getting a critical error running DNN on a customer's installation that we've done.

At some point (not the same time of day or period between crashes), the site crashes fatally. When this happens, there are no errors written to the DNN Event Log or the Server Event Log. I do NOT get an "APPLICATION_SHUTDOWN" event!!

The site then tries to start itself up a further 4 times (crashing about 10 seconds after each start). With 5 crashes in a row in this short a time period, IIS eventually shuts down my AppPool, and I have to manually recycle the AppPool.

I have a number of modules that I have written that do various things, but I log everything within my own applications and I'm not getting anything ugly show up in the logs. Also, I've got the same codebase in about 4 other installations, most bigger than this one, and I don't get any crashes at all.

I've also taken an exact copy of the site (files and DB) and set it up on a TEST server in my office, and run a serious stress test against it, and DNN happily responded to everything I threw at it (as I expected it to).

So.. with everything that I've done, I'm stuck... Does anyone have any suggestions as to what to look for, where to start digging... what else I can possibly look for???

The technical details of the installation are:
- DNN 04.09.05
- SQL 2005
- IIS6 on Server 2003
- Partial Trust (Hosted at WebCentral)

Regards,
Grant

The app runs fine. Sometimes it crashes in 2 days, sometimes 2 weeks. While it is running I have absolutley NO problem with it. It runs fast, no errors etc...

Answers to your questions:
1) I know it crashes because in the DNN event log I get 5 "APPLICATION_STARTED" events in a row (usually about 10 seconds between each other). I don't actaully know what the user experience is as I've never "seen" the crash. I have trawled the IIS logs and I can see that pages are geting hit. I've written a page logging module (httpmodule) which effectively logs on BeginRequest and EndRequest. I did this is see if it was 1 specific page that was causing the crash.

2) When I get the AppPool restarted, it runs fine for a while then I get the crash again (can run for 2 days to 2 weeks)

3) Some are , some aren't. This is the only installation I have in Partial Trust, but I've developed for Partial Trust environments before with no problems (I have another app that has about 5 instances in Partial Trust on the same hosting provider).

Thanks for the thought, but anything else you can think of???

Regards,
Grant