All UI's appear as black

Hi all, I had this issue with the UI wherin when I build in Android and WebGL the UI's sunddenly appear black. Trying to troubleshoot it but I can't seem to find the cause of it. Here is a screenshot

The weird thing is if i build again (neither android or webGL) it will suddenly appear normal. So that's the fix I am doing right now. Just go on with my coding then just hope it will return normal again on the next build. Hope somebody can help me.

Thanks a bunch!