There is an unsaved comment in progress. You will lose your changes if you continue. Are you sure you want to reopen the work item?
Opening Project should work in background and show progress
Some .dspx project files take longer time to open.
I suggest running the "Open Project" as "Background Thread" and report the progress (update progress bar). I suggest creating the overloaded method SerializationManager.OpenProject(ProjectFileName, ProgressHandler).
Progress bar should be updated for every layer which is added to the map.