I also just tried and I did get the same error. I am using google Japanese IME.
However, I only got the error when I wrote いち and then hit spacebar to change it into 1。
http://puu.sh/q7CJi/9be5c6834d.png
This is the code that causes the crash.
The actor is a BP actor with a sphere component attached to a cube component attached to the default scene root. If I bind the action to a key it only crashes when I hit that key.
I hope this helps.
EDIT:
I just tried converting [1 1] into the coded representations commonly used by using [this tool][2]. There might be a hint here.