Backintime error when creating a new "profile":com.ubuntu.DeviceDriver.PermissionDeniedByPolicy: [...]

In Backintime, I am trying to create a new "profile" to backup the directory /home onto an external drive but this message error pop ups and I can't backup:

com.ubuntu.DeviceDriver.PermissionDeniedByPolicy: net.launchpad.backintime.UdevRuleSave.

Can anyone manage to reproduce this unexpected behaviour?

Steps to try to reproduce:

- open backintime-qt
- click on 'Settings' (the icon with tools)
- on the first tab, click 'Add'
- write profile's name
- click 'Ok'
- select 'Mode: Local'
- select the path to the external drive (I also trying with a local path, same error)
- on the second tab, I include /home
- click OK

I am wondering if this issue is widespread (or just on my laptop), because if it is, it's preventing new Triquel users from creating backups (I already have backups running, I was trying to create an additional one).

For now, I am using rsync alone to create that additional backup.

Related https://trisquel.info/en/forum/backintime-error-when-i-try-update-snapshot-path-comubuntudevicedriverpermissiondeniedbypolicy