**UPDATE. I believe that the Plays TV Recording service was the culprit. Leaving BigBox open overnight see if it is stable with this process disabled.**
I am having extremely similar crashes, didn't seem to happen until i added the Playstation 2 as a system. Not sure if this is still a common issue. BigBox will also crash when idle inside a system game menu and a video has played through twice or more. I have pretty good hardware, Asus 787 Deluxe, i7 4770 K. 4GB Radeon R929OC, 32GB Corsair Vengence, 700 GB SSD Samsung. Fresh install of Launchbox. Not sure how to diagnose the issue. Error reported as 'Unhandled exception at 0x00007FFF427F319B (ltc_game64-116096.dll) in BigBox.exe: 0xC00000FD: Stack overflow (parameters: 0x0000000000000001, 0x000000A85D343918).' I have all of the media and metadata synced and downloaded from the Launchbox/ Emu Movies servers. Boxes/Fanart/Videos etc. Only customisation is banner art with modified reignstumble art. I also use rocketlauncher exclusively to launch. Maybe i exported a dodgy PNG? I will try to reproduce under different circumstances. Will BigBox generally slow down as more and more systems are configured?
Really loving the Front-End though, swapped from HS and never looking back.