Issue
I am using IntelliJ Idea 2017.3 latest release in Ubuntu 2017.10 and shortcut Ctrl+Alt+Left/Right doesn't work.
Whereas from menu Navigate -> Back/Forward works fine.
Reference : https://www.jetbrains.com/help/idea/navigation-in-source-code.html
Solution
Ubuntu has a shortcut Ctrl+Alt+Left/Right to navigate between workspaces. When i changed it under system settings, IDE is able to pick up the shortcut.
Answered By - Samy Answer Checked By - Katrina (WPSolving Volunteer)