My bad
You'll need
KotOR Tool. With this tool, you can extract game files for modding purposes. In your case, you'd want to extract that appropriate .2da file that the mods you are trying to install use...
I would right away think that it's not a problem with CSArena since that is
stoffe's mod and well, she made the program to begin with
hehehe..
Avol's I wouldn't think either to be honest since most of his mods are quite popular around here and I haven't seen this problem reported before.. but again, you never know when dealing with computers...
The only thing I can think of is since you're listing a 2da-1 extension, is that somehow the file was copied and pasted in the same folder where such a file existed already (Windows tends to place a -1 to anything it copies with the same name).. it shouldn't have been placed on the actual extension name, but again, computers are funny like that...
Double-check to see if that's the case. If so, kill the -1 portion so that only the .2da exists...