if too many tabs are opened they are automatically closed on firefox 57

[Selmi]

i have really a lot of bookmarks in 'read later' bookmark folder
i use 'open all in tabs' and rely on this addon to limit them to some sane amount
before firefox 57 it worked well, after upgrade to firefox 57 it opens tabs, they start to load and after few seconds they are all closed
i set addon to open max 50 tabs. later changed it to 25, it didn't helped