Map Not Saving

I’m building a level in 4.11 for a class, and I keep running into this same error every time I try to save- the map itself, just the base first person map, isn’t able to save.

The issue began sometime around when I added a new actor- a button the player presses that changes a light, displays some text, and changes a boolean. I’m getting a similar “will not save error” from another actor, though I can go without editing that for now if I have to. Is there something wrong with my file or something? Why am I getting this?

I have same problem in 4.13. I thought that happens due to large size of map file. I’m working only with map, without blueprints editing.
Now i find only solution to “save as” my map under different name and then re-save on original.

guys i finally understand why… this happens because your storage in the hard is full .clear some space and it will work

open windows task manager, kill other ue editor,

This was my issue, didn’t notice I had two instances of the same project open. Thanks!

TYSM!