just updated the Andriod on my Samsung s4 and now im having issues with the phone.. my picture gallery wont open.. the phone is slow.anyone else had any trouble after updating

 

To Lollipop i assume? do a partition wipe, you won't lose any data or settings, if that doesn't help then do a factory reset where you will lose all your apps/data etc, so backup everything first. It will restore it with Lollipop with default settings.