There are issues when using adventure\creative when using a custom map, they need to be cleaned\wiped\rebuilt as shown in the video. Otherwise potentially the server just hangs after the ‘loading servers’ message.
This is particularly the case with the smaller sized 1024 x 1024 maps.
This video tutorial will teach you:
Learn how to:
Make a backup of your server files
Load a custom map into your server
Work around the problem of the server hanging’
Edit your database and clean it up
Credit: rheyansgaming
Notes: Make sure to zip up your map files into a zip file and upload to your gamemodes directory, once uploaded, unzip via the file manager.
If you upload manually by FTP it has been known for the map data to corrupt in some instances.