The first time it crashed, Using slayer... Hm. Got it.
I think I know a way to fix (This alredy happened to me, and I fixed it)
Easy steps:
1 - Go to your Blockland Folder.
2 - Go to: Blockland\config\server
3 - Find Slayer Folder
4 - Delete it.
5 - Reset Blockland
6 - Try hosting again.
If it works, fine.
If it doesnt works, Im sorry, but I cant help