We've been getting the same problem consistently. It either crashes when the game goes on for 2 hours or more or when a player joins in after about 30 minutes or more. Every RPT ends with the same error you described. We use quite a few mods, but we haven't been able to reproduce this on any other game mode. I will post my RPT when I get the chance

Edit:
Here's my startup commands

-port=2582 -MaxMem=16384 "-servermod=" "-mod=@CBA_A3;@ace;@ACRE2;@RHSUSAF;@RHSAFRF;@RHSGREF;@RHSSAF;@ALiVE;@aliveserver;@3CBFactions;@ACEAdvCPR;@ACEDiwakoRagdoll;@ACESplint;@Achilles;@Align;@BackpackOnChest;@BlastStandalone;@BreachCharge;@CTabDupe;@CUPTerrainsCore;@CUPTerrainsMaps;@Immerse;@MarauderGear;@SOUG;@Spyder;@Suppress;@tfvfac;@VcomAI;@hmd;@hmdrhs;@ProjectBJC;@ACEX;@USP;@offroad;@KAT;@Boxloader1;@Boxloader2;@torabora;@hazarkot;" -profiles=ARMAHOSTS -config=ARMAHOSTS\server\server.cfg -cfg=ARMAHOSTS\server\basic.cfg "-name=armahosts" -Server

We ran our test. We could not reproduce the error with Task Force Radio instead of ACRE2 after many attempts and playing for quite a few hours. We had players leave and try to rejoin, which usually causes the crash to happen, and no joy. Very odd.

I can't imagine ACRE2 is fully to blame because so many groups use it and don't report this problem. I haven't found any bug reports about this that mention ACRE2 other than this thread.