When I use KOTOR tool to extract a KOTOR I dialogue and try to re-open it, it doesn't work.

Supplication: Help me, I beg of you! :(

What are you trying to reopen it with? If it isn't a dialog editor then I think we may have found the problem. I highly recommend the one found here (http://www.starwarsknights.com/tools.php)

When I use KOTOR tool to extract a KOTOR I dialogue and try to re-open it, it doesn't work.

Supplication: Help me, I beg of you! :(

I have the same problem when I want to open an extracted dlg file with the conversation editor of Kotor Tool.

I use DLG Editor to open DLG files now after they're extracted.

If you want to open it in the Kotor Tools Conversation editor after extracting you either A) do open GFF File browse to where you extracted the dlg and select it and it will open in the conversation editor or B) do tools conversation editor then file open browse to where you extracted the dlg and select it. I personally use dlgedit but I do TSL modding and Kotor Tools does not have full support for TSL dlg's yet :-)