I was unfortunate to in the setup for synchronisation set one of my computers, A, to use encrypted passwords and the other, B, to encrypt all data. Now Opera on A chrashes on startup and the error is clearly in the Preferences file on A. Opera on B works.
What can I do to modify my Preferences file, which I would like to be as before this unfortunate mishap?
Thanks in advance for any tip.

I believe I have now figured out what's happening. Copying & pasting seem to append a trailing zero character, something that Firefox discards but Opera swallows. Further åäö are interpreted as åäö�

I have problems copying & pasting especially login info i.e. user and password into Opera (42) from some applications.
Exactly the same operations work without problems in Firefox. I guess it somehow has to do with character encoding.
What can I do. I am using Opera 42 on Ubuntu 16.04
H