I just checked Event Viewer myself and found the following errors that I believe were around the times BF6 crashed: EAAntiCheatService
ExitType: 95 (271) and (253)
Others have suggested manually reinstalling the anticheat software to fix this. I'll try that, I guess.
EDIT: I just looked further into the error history and found a single one probably around the time I finished playing BF6 yesterday (when it was still working):
Faulting application name: eaanticheat.gameservice.exe, version: 1.0.14379.0, time stamp: 0x68fe8282
Faulting module name: ntdll.dll, version: 10.0.26100.6899, time stamp: 0x234c0f50
Exception code: 0xc0000374
Fault offset: 0x0000000000117885
Faulting process id: 0x3680
Faulting application start time: 0x1DC50E675FB19AD
Faulting application path: C:\Program Files\EA\AC\eaanticheat.gameservice.exe
Faulting module path: C:\WINDOWS\SYSTEM32\ntdll.dll
Report Id: 766b2ce7-f0f6-460b-9546-07fb161836f8
Faulting package full name:
Faulting package-relative application ID: