Can view apn but cannot change it I've been using my iphone 5C with operator Mobile Vikings (prepaid) without a problem in Belgium. I bought a europe roaming pack and was hoping to use this in Croatia. 
But after arriving in Croatia, my APN settings changed and I'm unable to modify them... I can find them, view them, but when i modify them the changes are not saved... Am I doing something wrong?
What's going on? How can I correct this to use mobile internet again?

The phone is unlocked, using iOS 8.2.
Ok I found the solution. I Installed the right APN settings via http://www.unlockit.co.nz

Then I disabled the "EU internet" setting. 

update: I guess the "EU internet" enabled setting is the reason who I couldn't change the APN settings...