faridoddin This application failed to start because it could not find or load the Qt platform plugin "xcb"
I guess it is looking for libqxcb.so or libQt5XcbQpa.so.5 which should be already installed in your system because it is part of qt5-base package..
By adding .zip to Shadowsocks-Qt5-3.0.1-x86_64.AppImage name you can see the content of the package,
and there libQt5XcbQpa.so.5 is already included.
The AppImage is built on Debian Wheezy with custom built Qt 5.10.0, Botan 2.6.0, GCC 5.5
I think the problem is that this packages is compiled with and older version of QT
The repository https://github.com/shadowsocks/shadowsocks-qt5 has been archived by the owner and it is now read-only, 4 years ago.
To fix this I think you have to compile it from source.
