Using the DBM-11.0.2 release from 28 July. I vaguely remember this popping off well into the fight, but I couldn't tell you the exact situation.

1x Blizzard_UnitFrame/UnitFrame.lua:1114: bad argument #1 to 'UnitName' (Usage: local unitName, unitServer = UnitName(unit))
[string "=[C]"]: in function `UnitName'
[string "@Blizzard_UnitFrame/UnitFrame.lua"]:1114: in function <Blizzard_UnitFrame/UnitFrame.lua:1113>
[string "@DBM-Core/DBM-Core.lua"]:2858: in function `GetGroupId'
[string "@DBM-Core/DBM-Core.lua"]:7739: in function <DBM-Core/DBM-Core.lua:7736>
[string "=[C]"]: in function `sort'
[string "@DBM-Raids-Dragonflight/VaultoftheIncarnates/KurogGrimtotem.lua"]:441: in function `handler'
[string "@DBM-Core/DBM-Core.lua"]:1046: in function <DBM-Core/DBM-Core.lua:1033>
[string "=(tail call)"]: ?
[string "@DBM-Core/DBM-Core.lua"]:1046: in function <DBM-Core/DBM-Core.lua:1033>

Locals:
InCombatSkipped

This is probably being broken by this bug here: Stanzilla/WoWUIBugs#631

which means it's best to wait it out cause blizzard is supposed to fix it by launch.

What's happening here is that mod attempts to set icon by sorted roster order, using names from combat log. The names in combat log are messed up right now so it passes names to the group sorter that it doesn't understand, and throws error.

I'll leave issue open for tracking until blizzard confirms the underlying issue that's causing this error is resolved.

made function more robust anyways so at least it'll silence error if running alpha
4516a74

but the underlying cause, as I said, will also be be fixed blizzard soon™