SSL VPN: remotely authenticated (ADDS) but VPN fails

Hi,

one of our recently created users cannot use SSL VPN. We use Microsoft ADDS, users are imported & created through the console manually ("Prefetch Directory Users").

On dial-up authentication services return success...

2017:03:10-10:47:27 <firewall name> aua[18096]: id="3004" severity="info" sys="System" sub="auth" name="Authentication successful" srcip="<IP address>" host="" user="<ADDS user name>" caller="openvpn" engine="adirectory"

...but the SSL VPN client & live log say otherwise:

2017:03:10-10:47:28 <firewall name> openvpn[7324]: <IP address>:54521 TLS Auth Error: --client-config-dir authentication failed for common name '<ADDS user name>' file='/etc/openvpn/conf.d/<ADDS user name>'

There have been users created before and after this user was created which run perfectly.

We are running an SG230 (9.411-3).

Does anyone have an idea how to approach this issue?

Thanks so much in advance!