I recommend doing /kill @e. If you are using EssentialsX do /killall on the server console, but before you do that go to your server dashboard and disable command blocks.
1. https://minehut.com/dashboard/appearance (Make sure your logged on)
2. Activate your server.
3. Go to settings (of your server)
4. Scroll down and then find command blocks, it should be enabled but disable it.
5. Press "Save" under the command block enable thing.
6. Press restart
7. I recommend doing /kill @e. If you are using EssentialsX do /killall on the server console.