I've used Opera Classic's M2 email program since 2001, continuing with it happily even after switching browsers (I primarily use Vivaldi) Several weeks ago I discovered that keyboard input into M2 didn't work. I then found that my keyboard didn't work anywhere in Opera (v12.14; I never upgraded beyond that for reasons I don't recall), although the mouse did. I initially thought the keyboard in my Toshiba Tecra had failed, which would have been reasonable given that the Tecra is a decade old. I soon discovered that my keyboard worked fine in all applications other than Opera "Classic." I could download email into M2 but couldn't reply without cutting and pasting from another program since the keyboard didn't work.
I do daily backups, so I restored from increasingly older backups until I found one where Opera worked properly. I restored my most recent M2 email backup and things worked fine. Even then, however, I was afraid the problem might reoccur since I didn't know what had caused the problem. Sure enough, after a couple of weeks the keyboard in Opera failed again. My attempts to fix this have failed. I've unsuccessfully restored Opera to my latest setup. Even restoring my entire setup from the backup I used to fix Opera now fails, which makes no sense.
Does anyone have an idea of what could be causing this problem? A corrupt file or component of Opera? Why would Opera work fine and then fail later on? Any help you can provide would be greatly appreciated as I don't want to abandon M2 permanently (unless Vivaldi finally releases its stalled M3 client). For now I'm using web-based email but find it far less convenient than M2.