We have discovered that some learning management systems have the following issue with the Name field for the LTI link. (In Moodle this field is called Activity Name and is found under the Show Advanced button.)
If there is an foreign language accent mark in the Name field or the Activity Name field (Moodle), an error u'\xc1' or u'\xe9' appears.
Make sure there are no accent marks in the Name field or Activity Name field.