Forticlient suddenly doesn't want to connect

Hi'll

Last couple of day's I find problems with the forticlient in IPSEC mode.

Installations that have been working for months without a problem suddenly can't loggon to the firewal.

I uninnstall and reinstall, register new but it's just not connecting telling me if to check my shared-key and password.

It seems related to the PC the client runs on since it's authorizing the user.

I tested this with users that work on other client's.

I've switched these user over to SSL there it works.