Steps to Reproduce:
Drop the Oak Planks
/kill @e[name=Oak Planks]
Expected Results:
Oak Planks disappear.
Observed Results:
A syntax error occurs.
Comments 3
Does it work for you if you use quotes as suggested? Also, none of the built-in identifiers use spaces.
if its something with 2 words you putĀ /kill @e[name="Oak Planks"]