The Macintosh operating system imposes a limit on how many databases you can open at one time. Each open database uses three file paths (to the data, keys, and pointers files), and depending on the configuration and version of the system that you are using the limit on available databases may vary. I have browsed six databases simultaneously, but have not tested the limits of this feature thoroughly and would appreciate any reports of your own experiences.
You should probably let Free Text close all open databases before trying to build new index files, as parts of that operation require opening up to ten file paths. Be careful about appending files, calling up desk accessories, or doing other I/O-intensive tasks while browsing many databases at once!
