How to import custom structure successfully?

Status
Fixed
Issue description

So, after finally opening MCreator, I tried to import a custom structure that I made. But there are some problems:

1: How can the structure's interior be completely out of air (because in my case, they were full of dirt, stone etc)?

2: MCedit does export sctuctures, but it doesn't work with custom blocks. (the custom blocks are simply replaced by air). 

I checked some pages and there are no answers. Is there any other way to do this job?

Thanks in advance. Any help appreciated as always!

Issue comments

  1. Use structure void blocks
  2. Use structure blocks in Minecraft

Search this website and it has tutorials on how to properly use structures with custom blocks and with structure block on the forums.