This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
It sounds like your "preferred application" for web browsing is set to Nakmora, if Nakmora is a web browser (I'm not familiar with it).
You can probably set the default preferred application from your control panel. I'm using Fedora with Gnome, and it's on the System/Preferences menu there. Probably the same for Ubuntu with Gnome. KDE I don't know about, but I think you'll probably find it somewhere.
An IDE is no substitute for an Intelligent Developer.