I trying to TestFor an Item Frame placed on a block (with or without other parameters like precision of geographic emplacement, orientation, etc.).

My command

"/testfor @e[type=ItemFrame,r=10]"

make this result:

"[21:14:47] Entity type 'minecraft:itemframe' is invalid"

My other command

"/testfor @e[type=ItemFrame,r=10,c=1]"

To force the command block to select one Item Frame (the nearest Item Frame, placed on a block of course) give the result:

"[21:20:05] The entity UUID provided is in an invalid format".

Thanks you for advance.