So I made a grid building engine and got another bug tried alot things but can't figure out what's wrong.

When I open the grid building engine click grass and create a F like this it works fine
Then I press "K" to save the array works fine also array file is created.

I restart the program and press "L" to load the array
But the whole field is empty my F I made isn't there anymore

But then I started placing some grass tiles and I can't place any tiles in the location where I created the F.

I can place stone tiles over the "Invisible grass tiles" and place normal visible grass over the stone.

I created a event where I can't place grass tiles on grass tiles.
Maybe that's the reason why I can't place grass into these empty spots:

So saving an array works fine loading also but the grass tiles are invisible here is the mfa file I hope someone knows what up with this. Thanks!