Website is running a cached dll somehow after changing it

We had same problem but with minor complications, we have many many sites so a "clearing all temp" and restart IIS is not a good option for us. So we needed to be more selective in what to force a refresh on.

On our QA machine, under ... "C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files" I did a file explorer search for the partial file name of what we are trying to release. The file was found in a folder something like: C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files\root\4503212x\ad95664x, so I stopped app pool, deleted the folder, restarted and all was deployed then - great!

But .... We had same trouble deploying to production and the above did not work.

Long story short, the QA app pool was set to "enable 32 bit true", but production was set to "False" so the prod temp files resided in: "C:\Windows\Microsoft.NET\Framework64\v4.0.30319" instead (\Framework64\ instead of \Framework\ ).

If clearing temp files is not working - double check your frameworks, or look for files to refresh at the C:\Windows\Microsoft.NET folder level and below. you may be surprised.

Nuke your temporary asp.net folder contents. Not sure why the update didn't automatically get compiled, though.