Clients offline after reinstall

Hi folks,

a few days ago, I reinstalled my UTM9 to solve some problems with VPN connections due to "broken" files.

I reapplied my config backup I made before, but since then, my Endpoint Clients were only marked as offline in the endpoint management section.

So, how do I get them online?

Did the token change or something? hope you could help me..would be glad if I don't have to reinstall the endpoint software on all the clients.