Hey i´m trying to make a subclass for the Rogue but after i have set the settings to what is needed  to give a spell casting ability it wont work.

Tried for the fighter and it also does not work there. 

You actually need to give it a class feature named “Spellcasting” for it to work. (Not “spell casting,” “Spellcasting.”)

Tried that but that did not work. i Checked with a friend who made a subclass like this about 3 months ago and even with identical settings and features it did not work. 

Do this exactly:

Make sure that you didn’t get autocorrected with a space between “spell” and “casting,” it has to be all one word.

Under “Basic Information,” make sure “can cast spells” is yes, “Spell Casting Ability” is Int, and “additional spell list” is Wizard. “Spell Prepare Type” is —, and “additional specific spells” is empty.

Then, re-save the entire thing using that main [SAVE CHANGES] button under Basic Information.

Then, go and delete the current test character, wait 20 minutes, and retry it with a brand new test character. Make it 3rd level, add the subclass, make the character and go to the sheet and see if it doesn’t have spell slots.