Maybe its a problem with the SMB2 Mode of the new Windows Server.

Try these reg-File (copy the content into a plain txt-file, rename it to .reg and run as administrator)


Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\LanmanWorkstation\Parameters]
"FileInfoCacheLifetime"=dword:00000000
"DirectoryCacheLifetime"=dword:00000000
"FileNotFoundCacheLifetime"=dword:00000000





Restart Computer.... maybe it helps ;-)