I had the same issue after upgrading to glimpse 1.3, the solution that worked for me was to clear the temporary ASP.NET files, which are most likely here:
%TEMP%\Temporary ASP.NET Files
or here:
%USERPROFILE%\AppData\Local\Temp\Temporary ASP.NET Files
It looks like you've also asked this through the glimpse issues, where I've also posted my answer.