SQL Server: Problems with corrupt files or assemblies

Yesterday I found and fixed a bunch of hard drive issues. One of those issues resulted in my “Microsoft.AnalysisServices” assembly for SQL Server 2012 becoming corrupt. That in turn resulted in VS2010 throwing errors when I tried to use SSDT or do just about anything else. My exact error message was:

Could not load file or assembly ‘Microsoft.AnalysisServices, Version=11.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91’ or one of its dependencies. The module was expected to contain an assembly manifest.

There was an MS help link as well, but it basically took me to a page that thanked me for letting them know they needed to work on their documentation. It was a little less than helpful.

I tried several things to fix the problem.

1. Re-apply SP1.
2. Uninstall just Analysis Services.
3. Repair SQL 2012
4. Uninstall SQL 2012  (This mostly worked except I still had issues with SSAS)
5. Reinstall SQL 2012  (This worked, but still had issues with Analysis Services)

All of the above resulted in the same error message at some point and a non-working install of SSAS 2012.

I finally came across an article that talked about fixing the Global Assembly Cache. While not everything applied directly, it did get me started.

1. I tried copying the gacutil files as mentioned in the article. This didn’t work. The program ran, but didn’t do anything. I had to use the actual location for  gacutil.exe in order to do anything. This can be found in “c:\Program Files (x86)\Microsoft SDKs\Windows\” You’ll need to choose the appropriate version for your OS as well as the appropriate choice for x32 or x64. In my case, it was Windows 8. My full path to gacutil.exe was “C:\Program Files (x86)\Microsoft SDKs\Windows\v8.0A\bin\NETFX 4.0 Tools\x64”
2. I had to find my physical Microsoft.AnalysisServices.dll file, found under “C:\Program Files\Microsoft SQL Server\110\Setup Bootstrap\SQLServer2012\x64”
3. After that, I was able to run gacutil -if “C:\Program Files\Microsoft SQL Server\110\Setup Bootstrap\SQLServer2012\x64\Microsoft.AnalysisServices.dll”

After running that command, I uninstalled and re-installed SSAS under SQL 2012 using the standard add/remove features and everything is now working. I don’t know if anyone will encounter a similar problem with a bad assembly or assembly manifest, but hopefully this will help someone.