[Graphics] Game covered by an unwanted tile

[Slazmaz]

Not sure if this is the right category for this.

Well, trying out my hacked ROM for the first time this happened.
https://gyazo.com/32b33b3f925ea17c2d8d46ab914ceb47

These (sand)tiles are covering pretty much everything for some weird reason.
And the are not visible in advanced map.

Help?!

 

[Slazmaz]

It seems to be all "Block is covered by hero" tiles that this occurs to