EDIT: 


 Shaman
Shaman pointed out in Discord that my file was wrong in structure.
Please check if your .sdz contain a sub-folder; if you are new to modding like me, be patient to investigate the problem.
Now you may try this mod by typing
!game meteor
in a room
___________________________________I did minor changes, however uploading bring up error information
Resource upload results
No valid map/game found in the uploaded file
I guess it is the modinfo.lua 
return {
    name='Zero-K May Meteor Fall',  
    description='Zero-K with earlier Meteor Controller',
    version='Meteor', 
    shortname='ZK',
    mutator='1',
    game='Zero-K',
    shortGame='ZK',
    modtype=1,
    depend = {
        [[rapid://zk:stable]], 
    },
}
Not outcome so far. Thank you 


 Shaman
Shaman, very detailed step-by-step instructions but I still cannot get it run.