I have blogged about this in November 2013 which is almost 2 years ago.
run as admin (windows key + X) command prompt as admin
C:\Program Files (x86)\IIS Express\iisexpress.exe" /path:C:\Windows\Microsoft.NET\Framework\v4.0.30319\ASP.NETWebAdminFiles /vpath:"/webadmin" /port:12345 /clr:4.0 /ntlm
and then there was this stacktrace and error… I have not had this issue before. It was since the 4.6 framework was installed.
Thankfully I found this stackoverflow answer which resolves it:
open "C:\Windows\Microsoft.NET\Framework\v4.0.30319\ASP.NETWebAdminFiles\App_Code\WebAdminPage.cs"
in notepad++ and ctrl+g (go to) line 989 and give the string appId
the value of “1” instead of the stringutil.blabla
save and reload the page.
No more error on:
StringUtil.GetNonRandomizedHashCode(String.Concat(appPath, appPhysPath)).ToString("x", CultureInfo.InvariantCulture);
Good luck!