A small request, since you get this error that I can't reproduce myself.
Before doing as suggested in the thread linked to in the above posts, could you please download the latest TSLPatcher version, found here (
http://www.starwarsknights.com/tools.php#mctl), extract the TSLPatcher.exe from that archive and put it in the same folder as the mod installer you are having problems with, and then run it instead of that mod installer, and see if the error still occurs?
I've made some changes to how the progress log works in recent versions that maybe could solve this error, but since I can't get the error to occur myself to begin with (and only four others have reported it a few months ago) it's quite hard to test it. :)
EDIT:
@Below: Oh well, that's too bad. Nothing I can do anything about it then since I can't get the error myself for testing. The problem seems to lie in the Delphi VCL RichEdit control and the odd version of the RichEdit DLL files you and a handful of others seem to have. :(
You'll either have to switch to plaintext logging, or upgrade your RichEdit DLLs, as described in the linked post.