A workaround: 1. Activate "flight mode". 2. Start Opera Coast 3. Deactivate "flight mode".
Thanx! This works on my iPad Air2 and iPhoneSE !
Supplement: For me it seems to have nothing to do with the Version of iOS OR Coast! :
I have 10.2.0 on my iPad with Opera Coast 5.0.3 and it also crashes since beginning of February!
This combination worked for long time before!
The described workaround could suggest that Opera communicates to something at startup - which fails since beginning of this month... ?