I have a problem to place catalysts (my favourite weapon of choice). I was able to build two of them, but the last three was impossible. They didn't have the blue spot as the other two. I have also placed some buildings/structures on the planet with the systemdesigner.
So it's a system you made? Can you export that system, compress it to a .zip and post it here? (The compression is just to accommodate the "Upload a File" button on this forum, which doesn't accept .pas files.)