Dear friends,
After install Firewalld, Firewall-Applet and Firewall-Config bundle, the Mate Dock Applet start to work. I think some dependencies of that Firewalld bundle packages solved the issue. My system: Release 9 (stretch) 64-bit Kernel Linux 4.9.0-2-rt-amd64 x86_64 MATE 1.16.1 Best regards, Jorge
