1) packed wrong
2) bad .dds file
3) an error in your hand editing if you did any.
Options
1) repack and try again; or,
2) redo the latest change in your overgrowth with a known working mesh or texture; or
2)delete/remove overgrowth files/folders and restart (I find that you need to do your overgrowth placement in one sitting or it will crash)
To spare you many others freakin' out on ya, I suggest that the BF2Editor forums are the better place to find a solution. Dont forget to mix up your search terms when doing your research.
Good luck.