issues on the console:

screen position out of view frustum (screen pos 0.000000, 0.000000, 0.300000) (Camera RECT 0 0 0 0)
UnityEditor.dockarea: Ongui ()

Answer 1, Authority 100%

As it was noted in the comments, this error is related to internal unity-reasons. It can be ignored or updated the version of the editor to a newer one.