How can I copy/paste files via RDP in Ubuntu?

https://github.com/FreeRDP/Remmina/issues/243 says that shares show up using Remmina when you also enable sound redirection. To recap, here is what you have to do:

1. Create a Remmina RDP connection to the windows machine
2. Choose a share folder
3. In Advanced tab, change sound to local. Save it and connect

Then the shared folder appears in My computer in windows.
(If it does not appear, trying clicking Refresh).

4. Try restart Remmina if it doesn't work.