In reading through prior questions on this forum, I found an entry about formatting the Seestar's disk drive which stated that formatting can be done by the iphone app or by a PC connected by a USB cable. In either case system files are protected and the format should be in exFat so that the seestar drive can be read by a PC. Before formatting, I used the Diskinternals Linux Reader to copy all the data on the Seestar to my PC. Then I formatted the Seestar and copied the data back to the seeStar. So everything works fine now, and I don't have to use Diskinternals Linux Reader to access my data on the seeStar.
One thing I noticed: When I have connected my Seestar to my PC, the Seestar app is 'ghosted' on my iphone (it is frozen). If I press 'Only recharge' on my iphone, then the connection to the PC stops and I can use the app again.