Opera browser suddenly stopped working

A version of the Opera browser has been working okay in a Debian Jessie system for about 9 months. Suddenly certain features no longer work :-

(1) Can't open attachments in emails, especially PDF attachments.

(2) Can't use ALT-P to clear cache/cookies

Can anyone explain why this has happened, please.

The version of Opera being used is

opera-stable_64.0.3417.73_amd64.deb

Is there an HTML problem now with this version ?

Does the Opera version need to be updated ?

If so, which version is suitable for Debian Jessie ?