Dolphin's settings won't change!

Hello guys, I need help with something, it is probably a stupid problem but Dolphin won't save any change I make, I click "ok" to save the changes then I check the tab again and no changes have been done... I looked around and there was a old topic, a guy solved this by changing the directory of his Dolphin to C:/My documents , I tried that too but it doesn't work for me...
Help me out, please!