Issue in recognizing default browser on Xubuntu 14.04

Environment : Xubuntu 14.04
PPA’s version of Gedevelop. Package : 4.0.89003-1~trusty

Google Chrome and Vivaldi browser are installed.
Google Chrome is my default browser.

In start page, when I click on “Start a platformer game in 5 minutes link”, both Chrome and Vivaldi are launched.
In “Scene” menu, when I click on “Preview”, Vivaldi is launched instead of Chrome.

I actually do not know if the issue comes from Gdevelop, Vivaldi or Xfce.

Finally it was an issue with linux OS.

As vivaldi was installed it was called by the /usr/bin/x-www-browser executable ;

So I had to execute update-alternatives to change default browser :

sudo update-alternatives --config x-www-browser

And select default system browser.