The fragility of computer programs

For some time I have used mainly the Opera browser, which has about 2 percent of users on the web. I used it with a Gmail as a POP server. About a month ago the mail server stopped working. I couldn't do anything with Gmail on Opera, so I started using Chrome more frequently, and had almost decided to dump completely Opera.
I did try to fix Opera in this period, searching for similar experiences on the web. Just today I found that a single flag in preferences:advanced:security:security_protocols, namely the lack of enabling of TLS1.1, was causing the problem.

I have returned to using Opera as my main browser.