I set the application to run in Administrator mode and XP compatibility mode, but it didn't help.
Also,
1) When did the problem begin to occur?
Straight away.
2) Did you install the latest version of the mod?
Via Steam Workshop, so yes.
3) What version of the game do you have? (Steam, 4CD, KotOR Collection?) What region is the game designed for if it's the 4 CD version?
Steam.
4) Did you update your game as required by your game's region?
Steam is the answer here.
5) Did you install this over the previous version(s), or did you perform a fresh installation as required by the TSLRCM's read-me file?
Nope. Fresh install, first time on a new PC.
6) Did you use the TSLPatcher, if provided?
Used Steam Workshop, didn't see the need to as I only use one mod.
7) Were there any errors in the TSLPatcher installation?
Nope.
8) What other mods did you have installed? Please give an accurate list and provide links to each of these mods - even if they are found on this site. (We don't actually know them all!.)
None.
9) Can you be more specific about the error? At what point did it happen?
Like OP, straight after a combat sequence.
10) Have you tried re-downloading the mod?
...
It's not been the '90s for some time now, so IPv6 should do its job. Also, Steam Workshop will have secured a nice stable download for me. I'm not going to explore this route.
11) Have you tried using a different save game?
Yes.
12) Have you tried starting a new game?
Yes.