OPEN files with various suffixes from various programs (some better than others) What is the suffix of the file you are trying to open in FTM? You can see acceptable suffixes at the right side of the file name at the Browse dialog screen.
RESTORE *.ftmb files
It will also MERGE and IMPORT files
PS: I'm not sure what the difference in FTM between OPEN and IMPORT, but try Open first (if the suffix agrees with an acceptable one.) If that doesn't work try Export.
If you are stil having trouble to ancrestry.com and click on Help or call ancestry for assistance.