CIFS mount in FSTAB does not work after update

A few hours ago i made a full update via the software-center. The mounted shares allready worked fine, but after updating i just get this error message:

mount error(22): Invalid argument Refer to the mount.cifs(8) manual page (e.g. man mount.cifs)

This is how my shares are mounted in fstab:

//IP-of-server/samba-directory  /Path-to-mount-point/ cifs users,noauto,uid=1000,gid=1000,credentials=/path-to-credentials,iocharset=utf8,sec=ntlm   0       0

using

mount -a

does not show any errors.Trying to access the share with the File-Explorer directly (using smb://path-to-server) works fine as well.I have allready tried to use the "vers" option, but with no success.

using

tail -f /var/log/kern.log

returns

CIFS VFS: Unable to select appropriate authentication method!

Thank you for your help and replying