phase revit

[EnricoBertolini]

Good evening, I have a phase problem.
I created a renovation project then duplicated the views to create the state of fact is comparison. As soon as I change the phase of the factual state in the property of the view, in fact, the design disappears from the view (white sheet) with the consequence that in comparison I see all red. Has anyone ever happened?

 

[gfrank]

phases are a time sequence. The existing state is normally drawn, which by default must be in the "actual state" phase, so in the design phase changes are drawn, which in the comparison appear in yellow and red.
if you have designed everything in the project phase, the phase of the "actual state", is empty (there is nothing) and therefore the comparison shows everything in red.
However, check that phase filters are correct.