Hello Everyone, I Can Confirm This Is The Issues With Opera, Since I Also Have The Same Problem.. And Not Single Problem With Another Browser..
I Have Opera Version - Version:57.0.3098.106
And This error Usually occurs when we insert many file too uploading, // too many data to load, too many data to save // remember by opera,, despite so much memory ( RAM ) Available.. in my case, this error will occur using FACEBOOK CREATOR STUDIO,, when i'am uploading too many files in queue..
it will crash !!.. opera will crash.. on my profile also opera make faceboo NEWSFEED gone.. (www.facebook.com ) but not gone if i;am using m.facebook / iphone.facebook / business.facebook
this is the screenshot of what i'am doing --
so if you uploading many files.. use another browser until this is fixed..
![alt text](image url)