What map and version of Quake 3 are you running?
It might help if you set com_zonemegs to 64.
The server command seems strange because q3dmp15 appears to be a map, not a mod. Mods can be loaded by setting fs_game like that, but maps are typically loaded by just placing the pk3 in baseq3 and using the map command. So a typical command to start the server with that map initially would be "./ioq3ded.x86_64 +map q3dmp15".
I did a little bit of testing, and I encountered problems if the bots were set manually but only for one team (i.e. the blue side of the list). This occurred even on stock UI Enhanced on stock Quake 3, so it definitely looks like there is some UI enhanced bug involved here.
If the "bot selection" option was set to random, or if the bots were added evenly to both teams, I seemed to have better results. What is your experience with these options?
Another thing to try is to make sure sv_pure is set to 0, if there is an option for it in the UI settings. I don't really expect this is the problem though.
Edited 33 seconds after the original posting.
Is it possible to find a specific bot that always exhibits the problem, and the model pk3 containing it, so I could try to reproduce the problem? I'm not really experienced with how the bot loading process works in quake 3; maybe some bots just don't work in team modes for some reason?
Another file to try:
This one uses the qagame from ioquake3 (instead of the original quake 3 one) in case there are any relevant fixes there.
Try running "/logfile 2" in the console before starting the map. Afterwards locate the qconsole.log file (likely in %appdata%\Quake3\baseq3) and post it here. This should produce the full log, instead of the other method where the log was truncated somewhat and didn't have all the necessary information.
Here is another file to try:
Copy it to the same location:
C:\Program Files (x86)\Quake 3 NEW New Filesystem\uie
I don't know if this will work. I'm just trying to increase some limits in qagame since I don't know exactly which one is causing the problem.