Building Lighting Never Ends

I am new to Unreal. I have a new project and level. If I play the level, I get what I think I should get. If I build lighting, the ‘Building Lighting’ is always at 0% and the three ‘in progress’ dots keep cycling. I have let it go for an hour. The level only has a block plane as base with a cobblestone material, a cube with a granite material, a stationary directional light, a player start, and a lightmassimportance volume. So, I have no idea why the lighting build does not complete. Thanks.

Whenever I got something like that - simple restart would suffice. Did you try to create a new project from a template and building lighting there?
If you still have a problem with this one specific project - perhaps try to upload it online, so that others could confirm the issue?
ps. I also heard someone having similar issue and finding out that there was a problem with one of his RAM dices, but… don’t want to be a bearer of bad news.