This has happened to me a couple of times, and really sucks.
Create custom workspaces in a project. Save the project.
Open a new project or other existing project without closing previous project.
Custom workspaces in original project are destroyed. Quitting without saving does not rescue them.
Argh,
Chewy
Yeah, it’s messed up here too with multiple projects .
Workspaces are so close to being really great. But this issue (which has been around since at least the last couple of versions–please fix it, Steinberg!), and the other I’ve been harping about lately, but that doesn’t seem to be bugging anybody else, but really jams me up: the channel setting window focus being lost between recalls; please fix it, if only for me, Steinberg 
) really diminish workspaces’ practical utility.
I’m wondering if I could go to a backed up version of the session and salvage the workspaces from there… but I’m afraid to. Maybe when this project is done. In the meantime, once again, I’ve rebuilt the workspaces and, to avoid heartbreak and dismay, not to mention aggravation I don’t need in the middle of a project, will remember not to open more than one project at a time.
How about making these official issues, folks! Please.
Chewy