Put the summary of the bug you're having here
What I expected to happen was...:
Describe what you thought should happen here
What actually happened was...:
Describe what happened here
Steps to Reproduce:
1. Continuously place TNT
2. Wait for TNT to be placed
3. Occasionally it will change to sand, stone, or andesite.
thats the defult "null block" as all are #0001,#0002 ec so i think its a bug or a issue in your fills
(the thing that has all mine carft data, help i cant spell).