Backup non riuscito su hd esterno

Ho provato a fare il backup ma non viene completato a causa di un errore sconosciuto. Segue l'output. Chiedo se qualcuno mi aiuta ad interpretarlo. Sto usando DejaDup su Ubuntu Mate 18.04 con un hard disc esterno formattato in FAT32

Traceback (innermost last): File "/usr/bin/duplicity", line 1555, in <module> with_tempdir(main) File "/usr/bin/duplicity", line 1541, in with_tempdir fn() File "/usr/bin/duplicity", line 1393, in main do_backup(action) File "/usr/bin/duplicity", line 1511, in do_backup full_backup(col_stats) File "/usr/bin/duplicity", line 572, in full_backup globals.backend) File "/usr/bin/duplicity", line 454, in write_multivol (tdp, dest_filename, vol_num))) File "/usr/lib/python2.7/dist-packages/duplicity/asyncscheduler.py", line 146, in schedule_task return self.run_synchronously(fn, params) File "/usr/lib/python2.7/dist-packages/duplicity/asyncscheduler.py", line 172, in run_synchronously ret = fn(*params) File "/usr/bin/duplicity", line 453, in <lambda> vol_num: put(tdp, dest_filename, vol_num), File "/usr/bin/duplicity", line 342, in put backend.put(tdp, dest_filename) File "/usr/lib/python2.7/dist-packages/duplicity/backend.py", line 395, in inner_retry % (n, e.class.name, util.uexc(e))) File "/usr/lib/python2.7/dist-packages/duplicity/util.py", line 79, in uexc return ufn(unicode(e).encode('utf-8')) UnicodeDecodeError: 'ascii' codec can't decode byte 0xe2 in position 37: ordinal not in range(128)