Help ASP.NET app suddenly stopped working

[Guest]

I have an application that was developed in VB.NET. Its been in production
since October without any problems and that was the last time anyone touched
any of the code. Today I got a call from a user saying that on one of the
pages, a button click does not cause any action where previously it did. I
tested it and sure enough she's right it doesn't do any thing. I tested it in
my development environment on my workstation and it works fine. So I
recompiled on my workstation and redeployed the app on the server. It still
doesn't work. I've checked the logs and see no error messages of any kind.
The aspx pages load so that part works. Its just on this particular page that
the onclicked event for this button has stopped responding. I am at a loss as
to where I might look from here. Does anyone have any suggestions?

 

[Guest]

I've done some further research on this and I have discovered this problem is
effecting all of the ASP.NET applications on our server. I tried to debug
this by putting a break point on the first line in the onclicked event, and
the break point never gets hit. It appears that something is preventing the
runat=server events from being fired. Is it possible that someone may have
made a configuration change on our server that is causing this problem? Is
this something that a security policy of some sort might cause a problem with?