I'm not able to use wireshark "couldn't run /usr/bin/dumpcap in child process" [duplicate]

This message appears:

No interface can be used for capturing in this system with the current configuration.

(couldn't run /usr/bin/dumpcap in child process: permission denied)

Tell me how to avoid it.

As @Tim already mentioned - this problem was discussed before already. This post gives the proper solution - just tested it in 14.04 and it is still valid & working

The following is a 100% quote from here.

Open a terminal by pressing Ctrl+Alt+T and type the following commands:

sudo dpkg-reconfigure wireshark-common

press the right arrow and enter for yes

sudo chmod +x /usr/bin/dumpcap

you should now be able to run it without root and you will be able to capture.