Howdy,
Same happened to me (a few times..).
My final solution was deleting the entity, textures, meshes, etc. no trace left of it in my fpsc directory. Backup beforehand
Then, when you restart fpsc it will be missing a few files.
Open your level and most probably they are gone already.
Else FPsc has some kind of "?" entity and you can see the leftovers of the character in your game. You should be able to delete at that point.
Save game, restart fpsc and its gone (if all went well).
I think this problem occurs when your entity has a point of origin below (or higher) than should be for the engine. How and or what i dont know. All i know is when it happened to me, i moved an entity up (PageUp) (clicked Apply) and wasnt able to edit it anymore after that, nothing clickable.
You can try for yourself, go to level 0 and lower an entity below this level. It shouldnt be clickable after that.
With level 0, i sort of understand, but level 10/11 i can't.
Hope this helps anyway with deleting your character.
What you can to to really fix the issue, i don't know. I would check XYZ origins in my model, but im not a modeler. Hope someone else has a solution.
Grts
Anubis
-+- There are only 10 types of people in the world. Those who understand binary, and those who don't -+-
[Chipset:X58 CPU:i7.950.64 GPU:HD5970 RAM:12GB DDR3 WIN:7.x64 PRO FPSC:1.20.10]