Created attachment 122774 [details] screenshot of error message SUMMARY There are two actions (New tab, New tab) which would like to use the same shortcut (Ctrl + T). It might is an error. STEPS TO REPRODUCE 1. Download some file with Firefox 2. Click on down arrow icon (download) 3. Ask to open; OBSERVED RESULT Error cause by thread concurrency; EXPECTED RESULT Open the file manager on downloaded directory SOFTWARE/OS VERSIONS Windows: macOS: Linux/KDE Plasma: Buster | Debian 10 (available in About System) KDE Plasma Version: KDE Frameworks Version: Qt Version: ADDITIONAL INFORMATION
What application gives you this error? Is it Dolphin, the file manager?
Looks like Dolphin. This was already fixed in a later version.