For the last ~2 weeks, virtually every time I relaunch the browser I get the Subject error.
Any thoughts?
A screenshot of the error or the text of the error might help people to help you.
Unfortunately I don’t use the Avast Secure Browser (nor Chromium based browsers) so I haven’t got any personal knowledge this issue. I use Firefox as my default browser and it doesn’t close pages/tabs and generally no issue with that.
You could try this - Avast Secure Browser didn’t shut down correctly