When trying to add a storage device with virt-manager via:

--> Add Hardware -->  Storage --> Select or create custom-storage --> Manage
--> Browse Local 

nothing will happen.

After starting :

virt-manager --no-fork --debug

one see's this error message:

Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/storagebrowse.py", line 162, in
_browse_clicked
    return self._browse_local()
           ^^^^^^^^^^^^^^^^^^^^
  File "/usr/share/virt-manager/virtManager/storagebrowse.py", line 187, in
_browse_local
    filename = self.err.browse_local(
               ^^^^^^^^^^^^^^^^^^^^^^
TypeError: vmmErrorDialog.browse_local() got an unexpected keyword argument
'choose_label'

Commenting out "choose_label=data.choose_label" in
/usr/share/virt-manager/virtManager/storagebrowse.py does solve the issue.
However, I am unsure about possible drawbacks.