To do a proper recovery you should ensure that all files that existed in your installation are present in your restore installation. If you don't have backup of your EPESI dir, just only database and /data dir, you should first try to obtain all additional modules that you had in backuped installation.
It may be a problem when you restore database and there is stored info about some modules that are not present in your directories.
So I suggest to backup whole EPESI dir.
If you have only /data dir, your database backup, and your license key you should follow this steps:
1. Download EPESI in the same version as you had. Go through install process.
2. Reuse your license key and download every module that was present in your previous installation.
3. Now you should have all modules files required to restore backup properly.
4. Now remove data dir from current clean installation.
5. Copy your backed up /data dir into clean installation.
6. Restore your database overwriting current fresh install db.
7. Run EPESI.