To start working with ACE file you can open it in the Alignment Editor or import it to the UGENE database file.
To do this, open the *.ace file. The following dialog will appear:
If you choose the first option the file will be opened in the Alignment Editor as multiple sequence alignment. If you choose the second option the following dialog will appear:
Select the Source URL and Destination URL and click OK button.
The Source URL field in the dialog specifies the file to import.
The Destination URL field specifies the output database file.