No character was found for 'x'

I'm using macros within macros to pull up some stats. The problem is, it's able to to find every character based on their character sheet name, for example: @{Akthos|wisdom_mod}, except for one. This character is 'Alexis Mather', no space after the word or in the macro, no special characters, just first and last name. Yet it keeps telling me the character was not found. How can I figure out the actual name associated to the sheet for uses in macros. 

Select a token that represents that character, then enter @{selected|character_name} into the chat. It should kick out the character's name. Then you can try using that output and replace the "selected"... so something like: @{Alexis Mather|character_name} That should give you the same output as above. And if that works, then it isn't a problem with the character at all... so start looking at the attribute you're trying to return.