This issue started to occur about a week ago. Opera Beta 48.0.2685.16 (PGO)
If the browser was opened before sleep, after Windows waking up everything becomes very unresponsive. Pages won't load, extensions can't be requested, even Ctrl+T to new page won't load opera://startpage, just blank page. Disabling extensions, testing in private mode - no luck.
Restarting the browser helps, but it takes 2 (two) clicks on the X to close it, and then 2 clicks on the taskbar icon to start, and error saying "Can't open user profile directory, because you luck sufficient priviliges" pops up along with browser window. Also the browser will unfreeze after like 3+ minutes without restarting.
After this started happening, I checked for browser updates and some update was installed. Opera stable works just fine.
I use X230 laptop (so i use sleep mode a lot) with Win 10 LTSB on SSD, i5-3320m CPU, 12G ram, the user is in Administrators group.