My servers have both crashed numerous times since the release of 1.54
The server with more players has crashed more frequently.
All of which appear to be ACCESS_VIOLATION
The last crash logged this right before it crashed:
2015/12/01, 20:09:54 Error: can't resize AutoArray to negative size!
Exception code: C0000005 ACCESS_VIOLATION at 016B01B1
Here are dump files for 4 different crashes: https://www.dropbox.com/s/gz1i2cif85eug0l/Arma3ServerCrashes-1.54.zip?dl=0 {F27460} {F27461} {F27462}