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.

Hey, we believe fixed our issue. Our custom faction mod was spitting out tons of issue errors every single second. The moment it was removed ACRE2 has been working flawlessly. I'm not sure why this would be the case; we made it using the ALiVE ORBAT functionality.

Weird to say the least. We will confirm this when we play tonight. Thanks for helping out and looking into this for me the past few days. OP may want to try identifying if any of their mods does the same thing. You can see the constant errors and what I'm talking about in the RPTs I added.