IDE Stopped working...

Using Arduino IDE 1.x
1

I installed Arduino IDE on Fedora 23 LXDE it was working until I tried to add the Sanguino Board via the Preferences>add a web address thing. Something to do with JAVA any help much appreciated.

arduino 1.6.4-6 fc23 -- Yum Extender

[ron@localhost ~]$ arduino
Loading configuration...
Initializing packages...
java.lang.NullPointerException
	at cc.arduino.contributions.packages.ContributedPackage.findTool(ContributedPackage.java:63)
	at cc.arduino.contributions.packages.ContributionsIndexer.syncToolWithFilesystem(ContributionsIndexer.java:262)
	at cc.arduino.contributions.packages.ContributionsIndexer.syncPackageWithFilesystem(ContributionsIndexer.java:255)
	at cc.arduino.contributions.packages.ContributionsIndexer.syncLocalPackagesFolder(ContributionsIndexer.java:234)
	at cc.arduino.contributions.packages.ContributionsIndexer.syncWithFilesystem(ContributionsIndexer.java:180)
	at processing.app.BaseNoGui.initPackages(BaseNoGui.java:610)
	at processing.app.Base.<init>(Base.java:266)
	at processing.app.Base.guardedMain(Base.java:210)
	at processing.app.Base.main(Base.java:123)
[ron@localhost ~]$
2

ron_p:
I tried to add the Sanguino Board via the Preferences>add a web address thing.

What's the Boards Manager URL you used?