Excel Interop cannot open my file!
So a while back I made a website that uses the Excel interop (long story). Since I made it a while ago, the IIS configuration is not automated, and must be done artisanally.
So I immediately was not pleased. First I started ripping apart everything profile related with IIS, and nothing.
Eventually I stumbled across something on stack overflow to summarize make sure
C:\Windows\SysWOW64\config\systemprofile contains a folder called
Desktop. If you are on 32 bit you need
c:\Windows\System32\config\systemprofile to contain the
Pretty much desperate, and out of options I gave it a shot. Somehow it was the fix, although it pains me to say this.