Bad Zip File error
 

I am getting a "Bad Zip File" error when trying to write a cdg using kma format files. Does anyone know what I am doing wrong?

Try playing the ZIP file in the Play screen. The error message is telling you THAT zip file is bad. It may be it was zipped with "Max Compression" which MTU does not support. IF... that is the case, unzip it and use any other compression than Max.

Please read in the manual about zip files and errors.