Lighting worked, but now completely black

The lighting in my map was working, and I haven’t had an issue for months while working on this project.
The other day, I opened my testing level to make some changes, and when I went back to my main level the lighting was broken. All meshes were pitch black.
The only “solutions” I could find was making sure my meshes had proper light maps. Which I have had since the start.
So I don’t understand why I’m encountering this problem all of a sudden.
It’s make it really hard to level design when I can’t eye things in game properly.

Hello DarthNerdist,

You said that you have been working on this same project for months with no issue.

Is this only happening in this one map in your project or multiple levels? If this is only happening in one map, could you post a link to a dropbox with a sample project where this is happening?

Thanks,

So, I just restarted my computer.
And that fixed the lighting issue.
Possibly loss of memory was the issue.