Can't open database

This problem has been canvassed widely and I’ve read all of the relevant posts but none of them work for a database I have that just won’t open. It does a couple of peculiar things that may give a clue to people more knowledgable than me.

If I use File>Find & Open, right-click and choose Open data sheet only, I get the beachball spinning endlessly and Menu Meters shows that Panorama X is working away, using 100% CPU (spread across four processors), so it’s doing something - knocking on the door perhaps.

If I right-click and choose the Open with no windows option, nothing happens. Checking with Memory Usage shows that the file has not opened.

Any other ideas?

What happens when you open it with the menu command File > Open?
What happens when you use a double-click in the Finder?

If both ways are not working, I suspect a problem with the access rights. If they do work, there might be a problem with the Find & Open wizard.

In both cases, Menu Meters shows 100% CPU usage (with usage varying constantly on each processor) , the beachball spins and nothing happens - like forever.

If I •Show package contents* and open the data.archive file with TextEdit, I have access to the data sheet which shows the contents, along with lots of (presumably) binary characters. The other files in the package are not very helpful.