What version of FlashFXP did you upgrade from?
If you upgraded from a v3.x then FlashFXP will attempt to automatically import your sites and settings based on the registry keys for v3.x, however if FlashFXP is unable to find details of your previous installation in the system registry it will not be able to automatically do the import.
If you did upgrade from v3.x this installation is still on your computer, we do not remove it when installing v4.x.
You can start v3.x and perform a backup and then restore the backup from within v4.x
Please see the following guide for additional information.
https://oss.azurewebsites.net/forum/freque...iguration.html