Changing A Brush.

[WARP-10]

I'm having trouble changing a semi-solid to a solid without other brushes (unrelated brushes since they are not selected) in the map from disappearing.

[Hellkeeper]

Doesn't mean they are unrelated. Might have some BSP cuts going through them. No easy way to fix this, just make sure your brushes are clean and aligned on the grid.

[[§Ŕ] ŤhěxĐâŕkśîđěŕ]

Check that it isn't touching some other semi-solid.

Also as Hellkeeper said, try to keep them aligned to at least 8 units...

[WARP-10]

I fixed it. I re-imported the map and before doing anything else I selected for it a solid then rebuilt.

If I try to make it a solid after the first rebuild and save it, it causes other brushes to disappear.

The ones disappearing weren't touching it or anywhere near it.

[[§Ŕ] ŤhěxĐâŕkśîđěŕ]

The ones disappearing weren't touching it or anywhere near it.

That's what she said.
It doesn't matter, it can be any brush in the map which is causing problems with others.

[Sinistral]

I've had this issue before and resolved it by right clicking on the brush and selecting Polygons>Merge

[[§Ŕ] ŤhěxĐâŕkśîđěŕ]

Yes, if they are coplanar.