WTF happened to all my bookmarks?!?

[A Former User]

A Former User last edited by

Mac mini (Late 2014)
processor: 1.4 GHz Core i5
Memory: 4 GB 1600 MHz DOR 3
OS X 10.11.6
Opera 50.0.2762.67

I just upgraded from Opera 50 -- which kept crashing -- to Opera 51. And all my bookmarks are gone. Several YEARS worth of bookmarks are gone. This has never ever happened with any previous upgrade and I've been using Opera for more than four years. Is there ANYTHING I can do or am I totally screwed?