I just spent most of this morning trying to fix MS Reporting Services. It broke last night for some reason and finding out why has been a huge pain. I couldn't find anything about this on Google, so I thought I'd blog what I (eventually) found here.
The Setup
First, understand that we've customized our RS installation so that users can go to http://reports.companyurl.com/ instead of http://reports.companyurl.com/Reports. Doing this has a hidden gotcha I've blogged about before, but it's been working pretty well for months now.
The Symptom
Starting this morning, the page at http://reports.companyurl.com started looking funky. Links were being created with the "http:" but without the actual host portion. In other words, what should have been http://reports.companyurl.com/Pages/Folder.aspx were instead coming through as http://pages/Folder.aspx. This was true for all links on the page including src references for images.
This problem didn't seem to affect the actual report manager Urls. i.e. http://reports.companyurl.com/Reports/Pages/Folder.aspx displayed (and functioned) just fine.
The Overlooked Culprit
It took me forever to dig out what was going on and it probably shouldn't have. I had noticed that updates had been installed, but I couldn't find anything recent that looked like it should touch Reporting Service Url generation. Eventually, I decided to check out a .Net Framework 2.0 patch that was undated in "Add/Remove Programs". It's from KB928365 and is considered critical. Hitting the update notes from MS shows that it's from two days ago so the timeframe is right even if I had to hit the update notes to find it.
Now, Microsoft doesn't actually include anything in the above resources that would tell me what exactly was dealt with in this patch so I still wasn't sure what the update might actually have to do with Reporting Services crapping out.
Fixing Reporting Services
Taking a chance, I removed that update. Reporting Services at the website root works again. Since this is an internal server behind the firewall, I'm not too bothered about it lacking that patch. Nothing runs there without some pretty heavy oversight anyway, so the update is more of a risk than our exposure from not having it. Still, I'd like to put a bee in the ear of the engineer(s) who created a patch that functions differently when it's in the website root than it does when it's a sub-application.