One day when trying to access a mapped drive i received an “access denied” if i tried to access the server directly using the share name it prompted for a username and password and even though the details are correct the box keeps coming back.
So i dis-joined it from the domain and attempted to rejoin it again but again got the access denied error message, after some searching it turned out to be SMB signing was turned off on the client machine, to re-enable i needed to go to the following registry keys
HKLM\system\current control set\services\lanmanserver\parameters
HKLM\system\current control set\services\lanmanworkstation\parameters
Requiresecuitysignature change to 1
Enablesecuritysignature change to 1
and after a reboot all was well again.