I installed Black Pearl and when I went to the workspace, I had the error:

Unable to generate a temporary class (result=1).
error CS2001: Source file ‘C:\WINDOWS\TEMP\hq-r-kii.0.cs’ could not be found
error CS2008: No inputs specified

I found an article called “K2 – Read the Troubleshooting instructions” by Jeremy Hancock which was bang on. Just in case his blog goes offline, the solution was…

Give all “Authenticated Users” the following C:\Windows\Temp permissions: Read & Execute, List Folder Contents, Read, Write

That fixed it for me. Apparently it is in the troubleshooting in the manual – but who checks that before Google these days? Well spotted Jeremy.