Xmarks crashing Vivaldi
I think Xmarks worked at one stage but broken again
on Vivaldi 1.8.770.56 (Stable channel) (64-bit) on OSX
Xmarks sync works for the bookmarks bar but when I try to go to Xmarks settings I get odd behaviour.
It first asks me for my Xmarks password in a local page
Then it goes to the Xmarks login page asking for my password
Then gets to the page and I try to chnage the profile
It then closes all tabs (one by one) in the current wiondow (or crashes or freezes)
Yeah, seems to happen to me as well in the latest beta version.
I installed xmarks again after having it removed so to get my sync back to work I went into the xmarks option and pressed the download button.
I fill in my login details and the syncing is done and works.
The first run wizard of xmarks doesn't work though. Crashes the browser indeed.
Not sure if this will help your problems but a manual download Xmark Settings>Advanced Settings>Manual Download> Download Bookmarks solved my sync problems on the one machine I was having problems with Xmark
Worth a try!