Hi, i have quite the few updates on this. Yes firefox on windows. Blue stacks version is 5.5.120.10.28 P64 (Beta)

It happens only when a twitch video tab runs.

It happens only on the first time i run bluestacks after a cold boot. No matter the combination of opening and closing firefox and bluestacks afterwards it doesnt crash after the first boot of bluestacks for the day.

It hard to express that but it feels like its a hard "close?!" firefox doesnt crash or have a crash error report neither generates a log on the crash log folder. There is history and restore of the last opened tab as i pressed the X button to close the window pretty much.

I was able to replicate this to different systems both hardware software. Always same bluestacks and firefox installation (moving both their folders/profiles from my main system)

I suspect firefox/twitch/twitch related firefox addons, one of these runs something on adb ? and when bluestack starts the first instance it wipes everything there?? 1

Seems not much attention to this, i guess very specific issue. Still weird interaction which might be with other such type programs as bluestacks. Regardless issue is resolved when updated bluestacks from 5.4 to 5.9