It was Version 60.0.3255.170 . Right now there was an update to version 62.0.3331.18 and it resolved the issue. There is a new valid certificate for the digital signature and the add-on is working again. Thanks for your help!
Posts made by singularity093
[Solved]program signature certificate expiredOpera for Windows
I'm experiencing issues with add-ons (1password) because of certificate validation errors. I noticed that the certificate for the digital signature of the program has expired.
Is this the right place for posting things like this?