Why do I get “An error occurred while validating. HRESULT = '80004005'” when building a setup project?

Question

Why do I get the following error when building a setup project?

An error occurred while validating. HRESULT = \'80004005\'

Answer 1

I know this is kinda old news, but my particular issue and solution are not specifically stated here (as far as I can tell - if I missed it, I apologize).

I had same problem. It would not compile my project, but had no errors. All I could see was "Build Failed". I opened up the "Output" file (Click View--> Output on menu), and it told me exactly which reference (in my case a .dll) was causing the problem.

I deleted and recreated the reference and it changed the reference name from Microsoft.Office.Core (which was appearently only a 32 bit version) to "OFFICE". Then everything worked great. -- Make sure to make a note of the path to the file you are referencing in the properties window... My new path was exactly the same, but the reference name changed anyway.... still scratching my head on that one...

So the moral of the story is... When you get no errors and your build fails, check the "Output" tab and it might help.