emClient loses Signatures

Hello everybody, I hope this is the right subforum to ask this:

I have recently changed the Passwords of Active Directory User Accounts,
and after that, on the Terminalserverprofile of said Accounts, their Signatures in emClient were gone.
The Terminalserver is a Windows 2012 R2 Server with the latest patches installed.
The emClient Version is 7.2.40748.0

Can anyone tell me why this is the case and maybe a workaround to try?