How to Stay in Phase when Revit Phases Disappear

Recently we ran into an issue where every phase in a project disappeared. The impossible situation of no phases happened. What's more the ability to add phases seemed to be blocked by the graying out of the Insert phases buttons in the empty dialog.

In the absence of phases in the project, elements that were existing or demo no longer had visibility overrides. We also discovered that we could no longer create new spaces, new sections showed nothing, and valves no longer broke into pipes properly.

After a lot of back and forth, our own Mitch Voss came up with a suitable fix.

1. Use Transfer project Standards to add at least one phase from a template into the current project. (If you bring all the required phases from an earlier incarnation of the project or a template, you will find they still won't work. Revit does really want an imported phase and will not function properly with them.) All elements will be assigned to the newly transferred phase. I prefer to name the imported phase "DO NOT USE".
2. The good news is that the functionality of the Phasing dialog is returned. Meaning you can now create the required phases. Since these phases were made in the project (as Revit expects), they will function correctly.
3. Now open up a 3D view and select everything. Filter out as many unphased categories as you can and change the phase of these elements to the newly created "New Construction" phase.
4. Now you can cherry pick existing or demo elements to move to appropriate phases. Views and schedules can be changed to an appropriate phase all at once by selecting them in the Project Browser and changing the phase in Properties.

It's a good idea to verify that your Phase mapping is still in sync, but it seems to recover nicely on its own. It is a little bit of effort, but seems to be working quite well. It also won't take much to automate this process with a macro, if you are into that kind of thing.

Good luck and Stay in Phase!