Environment : Xubuntu 14.04
GDevelop package is installed from GDevelop PPA mentioned in Ubuntu launchpad. The package version is : 4.0.89003-1~trusty.
Once Platformer tutorial finished, in the menu “Scene”, click on “Instances” icon in the ribbon, then a popup is appearing “Instances list”. In this popup, inclination angles of objects are given in degree, but the degree symbol fails, there is an interrogation mark in a black square in its place.
You can see an illustration of this issue in the joined screenshot.