You're probably creating a zip file of a folder of the files, instead of just the files themselves.
No,no. Reason only in XML, i dont no how to crate him properly and what string of code should be in it for correct work.
<manifest> <name>Example Mod</name> <author>Example Author</author> <description>This is a example description of an example mod.</description> </manifest>
Copy/paste this doesnt want to work properly. Ofcorse with this <?xml version="1.0" encoding="utf-8"?> Doesnt work in note/excel , but work with NotePad, at last!