Scripts

I fixed it, but even in the regular editor, I see that there's something unclear in my script.

Create a new, empty map.
Place two heroes on it (yours and an enemy's).
Place single-cell impassable objects around your hero, and make one cell a region.
Name the region "Block".
Write the script (only this one):

SetRegionBlocked ("Block", nil, 1);

Run the map and check if your hero can pass through the block.
The region should be blocked.

After that, reply here with the result.

Added 1 minute ago

Yes, the properties say: file type "DDS" (.dds)

Does the FORMAT match the description in the xdb file? TF_DXT1
Are the height and width divisible by 4?