Hi, in first sry for my bad english. i have a Brand New Windows server 2012 With Plesk . ASP 8.5.9600.16384 ASP.NET 4.5.1 FastCGI Support 8.5.9600.16384 Perl v5.10.1 built for MSWin32-x86-multi-thread PHP 5.4.30 PHP 5.5.14 Python 188.8.131.52 SSI 8.5.9600.16384 (just change the upload and Post max size ) Set up Forum no Problem but when i want Install or Deinstall anything then stop the Prozess in the run/defered Prozessur. Error say just : Internal Server Error The server encountered an internal error or misconfiguration and was unable to complete your request. But i have nothing in the server log ??? and i have make the latest update from xenforo . Rebuild not work same error .