Gray Line on My Default scene.

Hi everyone. I’m going crazy over this. I was just working on some landscape project sculpting then texturing. After I build my lighting the scene suddenly had some gray cross lines. I restarted my project. And my default scene is suddenly like this…

How do I get rid of those lines? Please help. Thanks in advance.

Hi, looks a bit like unreals default grid, try to change the size of your grid to something like 100 (currently you have it set to 10000).

Thank you.