Vivaldi removes currentSession after exiting browser.
I happens not every time, but maybe twice a month after i close browser or it crashes, it remove all opened tabs and then shows clean session. Everything is fine, but this bug annoys me as hell. Can you add some backup functionality for current Session or current Tabs file?
The "lost" session should be accessible through the "trash" icon in the upper right corner of the browser window. It should be an entry saying: "Window with x Tabs" and there you should find all the tabs that disappeared.
Do you know the circumstances when Vivaldi closes the session and you lose all of your tabs (apart from the browser crashing)? Perhaps you have multiple windows of Vivaldi opened? In that case, Vivaldi always saves the tabs from the last closed window. That's one of the easiest ways to lose all of your tabs unintentionally...
Unfortunately i had only one window opened. I just closed it as always. I even don't know how to reproduce this behaviour.
Btw thanks for "Window with x Tabs" tip. Didn't know about it.
I've had this issue too, but it only happened to me like two or three times and last time it happened was quite some time ago, so it doesn't really bother me. I just thought that maybe you would know a little bit more about a possible cause for this in your case (since it's been happening to you more frequently).
Anyway, I think that the "Windows with x Tabs" entry on the closed tabs list is a good enough substitute for an actual solution...
I have no clue, honestly. But my home pc has huge uptime (about 2 weeks or more) and when i decide to reboot pc and close browser, a have a chance to lose all my opened tabs.