In order to save your ACL configuration you need to export UIDs and GIDs.

Please follow the steps:

1. Connect to your Open-E WebGUI.
2. Go to Configuration->NAS Resources->Users->UID Mappings. click download and save your "Users" database.
3. Repeate the previouse step with "Groups" and save it.

To import the 'Users" and "Groups" files, go to Web GUI and once again click on
Configuration->Nas Resources->Users->UID mappings (upload/download) then upload saved "Users" / "Groups."