Hi,
There was an old thread on this. I tried the things the OP did to attempt a fix. So far, no joy.
Running Firefox 115.19.0esr (64bit). My mail host is us1.providedns.com:[port #] and they are running Roundcube email.
I installed Mailvelope extension today. Roundcube --> Settings --> Encryption shows me the error message that is the title of this post. I am able to turn on the "Use Mailvelope main keyring" option ON.
I can open the Mailvelope extension and encrypt / decrypt stuff there. Zero integration with Roundcube though. I have added the us1.providedns.com:[port #] domain as well as the Roundcube.net domain. API == ON.
I thought I would be able to encrypt / decrypt in the Roundcube tab. So far, not so.
Any insight or assistance is most greatly appreciated!
Best day from FLA~
Karl