I have installed ArcGIS Server10.1 in my machine(windows 7 Enterprise sp1 64bit) which was working fine,suddenly one day the server stopped and not responding at all. When tried to start the machine from arcgis server manager it pop up this error "Failed to start the server machine "Server Name",Invalid byte 2 of 2-byte UTF-8 sequence." also when tried to remove it pops up this error "Failed to unregister the server machine 'Server name'. Invalid byte 2 of 2-byte UTF-8 sequence
I have tried to re-start the arcgis server from services, restart iis, delete the machine files manually(arcgisserver\config-store\machines) and tried to add(registered successfully) and start server machine (same above error) but no success.