Also make sure your meta .xml file is valid.
If its dd then ghostmode must be turned off, if its dm/race it must be turned on, make sure you set gamemode to race, if there is respawn, set it to none, only if race, set time to 5 secs.make sure, in meta file your map is named this way [DD/DM/RC]Map Name.
And you should name the zip file like mdbelen said depending on DD/DM/RC name it race/[dd/dm/rc]mapname.zip.
If you get confused on meta file, download notepad ++ it ll be easier editing text with it.