After a power loss none of the Comfort Paneles (6AV2128-3MB06-0AX1) would get any values from the PLC.

The PLC has al the values as we can se in the TIA portal and the Comfort Panels are online and accessible remotely on the right IP adress as they where before.

Several thing have been checked:

The time: 

If we change the time on the PLC the time on the Panel changes.

Reinstalled the Firmware and the application. 

Several restarts, 

Now in the Panel I have found one error message:

ID:53752 

Computer1 (ucp-3013891D31CB): PLC certificate is untrustworthy. Manual trust is not possible for -upc30138931D1CB

Could this be a certificarte problem? I don't belive that we have had any certificate before?

What certifivate is needed? 

Why now?

Is this the issue or is it something else that can cause this behaviour?