We run a CodJumper server with lots of custom maps, and hit a bug worth sharing.

Symptom

On some custom maps, players show up as the red "FX" sprite instead of their model.

Cause

The engine only keeps about 200 .arena map declarations (mp\ + usermaps<map>\ combined) and silently ignores the rest, roughly in alphabetical order. A dropped map loses its allieschar / axischar, so players have no model.

The client's table counts: our server read the factions correctly, but a player whose game folder had 354 declarations (an old grouping file plus one arena per map) still saw the bug.

Fix

Stay under ~190 declarations, on the server and on the client side.
One arena per map, no duplicates, no leftover grouping file.
One big .arena for every map doesn't work: it gets truncated around 55 KB.
Forcing factions in GSC doesn't help, because the client uses its own table.
After dropping to 163 declarations, the bug was gone:

Suggested fix for the Plutonium team:
When a usermap loads, the client and the server could read that map's own usermaps\<map>\<map>.arena directly, instead of depending on the global table built at startup. The loaded map would always get its factions, no matter how many maps are installed.
Players who download lots of custom maps and servers with big rotations would no longer run into this limit.

Exact threshold unknown (between 192 and 223 in our tests). If anyone knows more, we're interested!