Hmms.
This is just a thought (since I have done this before w/o realizing it).... but are you sure all of your mats are of the 'appropriate' file size / dimension?
I mean, if you have 1 mat in your list of mats to convert, and that 1 mat is actually 257x256 (instead of 256x256)...it will cause a very simliar 'unable' to convert error. View each bmp individually to confirm its size as correct; if not, resize it. Then try converting say 4 bmps to mat at a time (perhaps you were converting too many bmps to mat altogether).
And as mentioned in an earlier reply post.... you might want to make note of how many system resources you have (when you start the computer)...and 'during the converting process'.
You can find this out (on my machine), by finding the MY COMPUTER icon, right-click on it, Properties, Performance. You should see something like:
System Resources = 84 % Free
For my computer, i start at about 91 - 93 % efficiency.
This computer slows down or gets noticeable sluggish at anything under 50% (which is best to consider a reboot before continuing other applications).
Try doing a fresh reboot. Then try the 'converting' process when you have all available memory just for that purpose.
And *i could be mistaken* (or you typed in error), but you mentioned you wanted to convert .BM files as well?
( those are bmp files...but not used for textures in JED. BM files are used in Menu's, such as 'creating new lightsaber' pictures on the menu selection screen for picking saber color for a new character model. ) I think there is a program called BMut that does converting from and to .BM files.
JAS_Palidori
High_Councillor, Light Jedi_Master
JAS: Jedi Against Sith