Just to say this “hang” sounds to be what I’ve reported several times in the past. For what it may be worth let me add a little more detail.
Having a database that I’ve used for a number of years just suddenly “freeze” seemed to happen fairly frequently after I initially moved it to Panorama X shortly after that version became available. Your “corrupted preferences” fix (as you describe above) “unfroze” the database on at least some occasions. Other times I had to revert to a saved copy.
This problem has become quite infrequent and I’ve had this same database “freeze” only once in recent months. On that occasion refreshing the preferences file did not revive it but I recovered it from iCloud.
I can report that other databases operate normally if opened at the same time my main database is frozen. With an active problem I’ve been quite hesitant to open other databases until I’ve resolved the problem and have only done so occasionally to see whether the problem was global or only afflicted the one frozen database. I’ve not experienced a “freeze” while running any of my dozen or so other active databases but I run then quite infrequently.
I’ve never experienced a frozen database upon initial opening, only while actively doing data entry, sorting, scrolling, or the like. I can’t tell that any particular activity is associated with freezing, only that it occurs quite suddenly right in the middle of an activity. At that point after closing and reopening the database looks normal but remains frozen where it had stopped before.
I have only one copy of Panorama running on one iMac computer so iCloud shouldn’t be trying to synchronize across platforms I wouldn’t think (I do have a second MacBook and and an iPad, which iCloud does recognize but I don’t have Panorama installed on the other computer) I run Panorama from a local disc and adhere to your earlier recommendation not to run the database from the iCloud copy. I do save the database to a copy on iCloud, however, and as a last resort have been able to recover the “frozen” database from an earlier copy on iCloud.
The only advice I can offer is to save the working database as well as a backup frequently. Interestingly on at least one occasion closing the frozen database and reopening it from the local drive has worked. Most often, however, the local copy will not run and I revert to the saved iCloud version.