When UGENE starts, an error is shown:
[ERROR][17:20] Task
{MAFFT validate task} finished with error: Can not find expected message.
It is possible that the specified executable file C:\Program Files\Unipro UGENE\tools\ext_tools_win_64-bit\mafft-6.901\mafft.bat for MAFFT tool is invalid. You can change the path to the executable file in the external tool settings in the global preferences.
And MAFFT can't be used to align sequences.