Today, I opened my data_xxx folder to find that it was missing a ton of stuff. There was no ZE, no .bat files, the default README was gone, and only the folders remained. So I took a copy of ZE from my Arena A17 folder, took VM from the default data folder, and got the rest of the files from A17 and data. Then I did a little work in ZE, and tried to munge. I didn't bother to read my munge, and went to BF2 only to find it was not there. (It was the first munge.) So I munged again and this time I read what it said and at the bottom, it said this:

A possible solution would be is to revert your data_xxx folder back to its original state without the missing files you moved into it from the sources you mentioned. Now cut and paste your data_xxx folder to a different location like your Desktop. Then go to VisualMunge (the one from the Start Menu) and create a new world with the same exact modID as your data_xxx folder. Once that is done, cut and paste back your data_xxx folder into the BF2_ModTools folder, letting it overwrite the new data_xxx folder.

Thanks AQT, it works now.