You have made an error in whatever entity files you've changed. Most files point to other files within the game (other resources located in other directories) and if you just edit out some names, the files "break". you must mod the rest of the files in conjuction with whatever else youve done
eg.
if you mod the research tree and add another field for Gauss cannon research:
- you also mod the player entity file, at research avail to that race.
- you also have to mod the namestringID pointing back to entity file
- you would also mod the descriptionstringID again pointing back
- you also would have to point to whatever HudIcon file you wanted
- mod out any prerequisites to allow this to be researched
- ensure that the new icon for the research is not over another block position
****make sure you spell everything EXACTLY!!! It's usually that simple..****
If I made a simple spelling error in the example above (or any other mistake) when I loaded the mod, and moused over the new tech, the game would crash to a mini dump file because I would have "confused" it.
I hope I didn't confuse you (I'm very tired, and am having trouble staying awake right now..)
But the point I'm trying to get across is you may have missed some file associations...hope that helps, key is to work slow, check, recheck, check again.
I should have just said that
As