Vivaldi disappears in the background, but it's still running.
At times, Vivaldi disappears in the background but it's still running.
Same happens to me, I'm using Easter Snapshot 220.127.116.11 on Linux Mint 17.1 with MATE. No idea why… I think it's related to the flash plugin. Hope they fix it soon.
EDIT: 64bits version, just in case