I encountered a nasty bug last week: I was unable to extrude a BSP – those basic UE4 meshes used to prototype levels.

I still could select faces but it’s like they were inactive, I couldn’t move them and, of course, extrude them. All was fine with edges and vertices and the problem concerned only a single project, all others were fine.
So I thought I had toggled a preference inadvertently and replaced my projects settings with those of another project, to no avail.

I submitted my problem on various UE4 discord channels and even on the official UE4 boards, no one ever answered my question.
Disheartening and, to be honest, I was losing confidence in the tool: I don’t want to live through the bugs I had to face in NWN ever again, my own bugs and more than enough to deal with.

I finally found the problem by myself: there are 2 different config folders in an UE4 project, one at the project root and another hidden somewhere deep inside the structure. Very, very, very poor programming if you ask me.
I started a new project, moved my files in it and the problem was gone.

But my confidence was gone too.

I’m starting to work again this morning, I’ll see how things pan out.