Might be good to check https://reddit.com/r/uBlockOrigin/ to see if anyone else is having the same issue. But, always mention whether you're using the one from https://addons.opera.com/en/extensions/details/ublock/ or the one from https://chromewebstore.google.com/detail/ublock-origin/cjpalhdlnbpafiamejdnhcphjbkeiagm and what version you have.
It's also a good idea to mention whether you're having this issue in regular Opera (Opera One) or Opera GX or both and what specific version(s) of Opera as seen at the URL opera://about.
It's also a good idea to mention whether you have Opera's adblocking and tracking prevent turned on too or not.
It's also good to list the ID for the crash if Opera shows one for it.
It's also good to mention whether you get the crash in a test standalone installation too or not.