iFolder 3.9.2 and 2.x client can coexist on the same computer, but they are not integrated and their software should not be installed in the same folder. If you plan to use iFolder 2.x on your computer, you must comply with the following restrictions:
Any local directory where you store your iFolder 2.x data should not be converted to an iFolder.
Any directory that contains a local directory where you store your iFolder 2.x data should not be converted to an iFolder.