UI dissappeared (graphic rebuild loop error)

I have most of my UI disappeared randomly. I recently made no changes to it and it just threw a bunch of errors when I opened Unity and cant make out what they are about.

the errors say:

Trying to add Stat Bar (UnityEngine.UI.Image) for graphic rebuild while we are already inside a graphic rebuild loop. This is not supported.
UnityEngine.Canvas:SendWillRenderCanvases ()

I have not installed third party applications recently.
Can someone help me pls?