2 major command problem

The tellraw and title command doesn't work, it say :there's an error in the json and nbtdatatag. Also, We can't summon Fireball or other of those kinda entity like snowball ect. Please fix it , its very annoying. Also, there is other of those command bug with testfor a player item with attribute i'm sure there's more of it. I and all the mapmaker communauty will be bery glad if you fix those bug.