SUMMARY If you block all outgoing traffic using iptables, then the Dolphin file manager will work normally only in the user's home directory. When you try to open another disk partition, it will freeze completely. STEPS TO REPRODUCE 1. create a iptables-rule: sudo iptables -I OUTPUT -m owner --uid-owner myusername -j DROP 2. open Dolphin 3. try click on some of volumes in left panel OBSERVED RESULT Dolphin freezes EXPECTED RESULT Dolphin should open the section and show its contents SOFTWARE/OS VERSIONS Windows: Linux/KDE Plasma: Ubuntu Studio 19 with last updates and Kubuntu 18 with last updates ADDITIONAL INFORMATION The same behavior is observed for the Dolphin version 17.12.3. Interestingly, having real access to the network does not affect the appearance of this problem. That is, if you disconnect the Internet cable from the PC and do not create a firewall rule, then Dolphin will work well, but if you turn on traffic blocking, then a problem will arise with the disconnected and connected Internet cable. This is a very big problem. I like Dolphin, but I can’t use it, because I use network access through the white list of applications.
What happens if you access these "blocked" network shares from Konsole, e.g. using "ls" or "dir" command?
(In reply to Christoph Feck from comment #1) > What happens if you access these "blocked" network shares from Konsole, e.g. > using "ls" or "dir" command? You did not understand. Not network shares hang. The WHOLE DOLPHIN hangs. I’m not trying to access network shares (this is impossible, because I blocked the network). I am trying to open a regular partition of my regular hard drive.