SUMMARY I was using krusader to copy files from one sftp directory (on one server) to another (on another server). After a few files, I get an error message that a file couldn't be saved. Then a message is displayed saying that an ‘internal error’ has occurred and that I should file a bug. Looking in the logs, I see the following suspicious line: kf5.kio.core: finished() called twice! Please fix the kio_sftp KIO slave (This is repeated, probably because I tried a number of times.) The issue is reproducable. SOFTWARE/OS VERSIONS KDE Plasma Version: 5.17.5 KDE Frameworks Version: 5.67.0 Qt Version: 5.14.1
State management has been reworked for 20.04 so this cannot happen anymore.
For others encountering this issue: I worked around it by copying first from one server to local storage and the from local storage to the other server.