Please follow this template when making a Bug | Glitch report.

1. Your in-game name: MoniVI
2. Game mode that the bug and/or glitch is effecting: Skywars
3. Description of the bug and/or glitch: Before a Skywars game starts, you can get a TNT gun from /shop and shoot TNT at your glass cage and therefore fall out onto your island. This means people can then shoot TNT around the map which in turn destroys the map. People then won't join that game as it's unplayable.
4. Video/screenshot of the glitch:

EDIT: Here's a video of what happens when you join a game after people have used TNT to blow up the map:

 

TNT explosions have been disabled in order to temporary deal with the issue.