Project Preview became blue

[Anonymous_6e4a774fff06edfea512c20b69e2feb0]

如下图所示，播放的时候是正常的，但是预览就很奇怪

[Everynone]

I do not speak Chinese but it looks a bit like Lightmap Density to me. You might have accidently hit alt + 0.

Try this: alt + 4

[sllleeper]

hahahahha noob question