/testfor (Most likely) returns null when testing for a player scoreboard value

(This is not a duplicate to what I have searched, and the command IS correct unlike others that I have seen. Excuse this ticket if it IS a duplicate.)

When using /testfor to check a players scoreboard value, using the _min modifier or not, it does not return anything, or it returns 'null'. If ran by a player, it also doesn't return 'An error occurred' or '<Player> didn't match the criteria'. As well in command block output, and comparators don't change.

/testfor @a[score_OBJNAME_min=<Value>

OR

/testfor @a[scpre_OBJNAME=<Value>