@the-blinded is correct. I have a similar setup - latest version of Opera, latest version of Sierra, 2011 MacBook Pro. WebGL works in every other browser but cannot be enabled in Opera. This is a bug in Opera.
Posts made by rwxr-xr-x
Where are news sources stored, or, can they be exported?Opera for Mac
I entered all my feeds into Opera some time ago, and now I want to use a different reader. It looks like there's no export option or any way to get my feed addresses back out of it. What file are they stored in on disk?