My map was working fine, I added three weapons, and started receiving the 400 fx error. So i commented out some lines in my dlc3 csv and recompiled everything, still got the error. I then removed the shell eject FXs from all of my weapons, recompiled, and still got the same error. I removed the weapons I added, recompiled, no luck. Generated a new map, transferred most of my files from the old map to the new one, no luck. I would very much appreciate assitance here and I can provide any files that need to be checked. Thanks in advance!

Here is a link for fixing issues with 400fx.
http://ugx-mods.com/forum/index.php?topic=5311.0

Your issue may be that you need to delete the mod from your appdata folder then build mod again. Not sure of the why, only that with working with others, they have had to do that at times like these.