@Kiryu-3 I think Edge switched to Chromium too a few years ago. We have 2 PCs, Win 11 Pro 24H2. Only one is affected. Unfortunately quite many differences in games, apps and drivers installed in those PCs. Interesting issue to debug. There are many things to try from disabling Windows Defender to switching Nvidia GPU drivers. Or enabling Windows Sandbox (it comes with Pro version at least) and installing Opera inside it.

I ran out of time. I had to get some sleep and now it's morning here and I must go to work.

Edit: Reddit thread suggested this is caused by Microsoft Family Safety. Sure enough, when I check the affected Microsoft account under Family Safety in https:// account.microsoft. com, there is now an Edge -tab, and a setting for protecting web content. It mentions the setting blocks all browsers except Edge. My son is 17 years old and I had already disabled all tracking, reporting and blocks for his account. He runs Windows as Admin on the PC! This seems something Microsoft just implemented/enabled by default.

Same here. One Windows 11 PC runs Opera fine. But on another Windows 11 PC Opera won't start. Logo appears, then nothing. The standard version of Opera, not GX or Air. Issue just appeared a few hours ago without anything that user did or noticed.

We installed portable Opera (USB) in affected PC. It didn't start either. But it did start up after Windows was booted to safe mode. Original, normally installed Opera would not run in safe mode.

While portable Opera was running, we opened settings and disabled hardware acceleration. Booted Windows normally, again portable Opera would not start.

Currently on the affected PC only Edge runs normally. Opera, Chrome, Brave and Firefox won't start.