[v1.5.5] TypeError - C:\Python34\lib\site-packages\jinja2\filters.py:712

OpenNumismat: 1.5.5
OS: Windows 10 32bit (10.0.15063)
Python: 3.4.4
Qt: 5.5.1
Locale: en

Traceback (most recent call last):
File "d:\OpenNumismat\open-numismat\OpenNumismat\Reports\Preview.py", line 311, in _templateChanged
File "d:\OpenNumismat\open-numismat\OpenNumismat\Reports\Report.py", line 166, in generate
File "d:\OpenNumismat\open-numismat\OpenNumismat\Reports\Report.py", line 174, in __render
File "C:\Python34\lib\site-packages\jinja2\environment.py", line 989, in render
File "C:\Python34\lib\site-packages\jinja2\environment.py", line 754, in handle_exception
File "C:\Python34\lib\site-packages\jinja2\_compat.py", line 37, in reraise
File "C:\Program Files (x86)\OpenNumismat\templates\wikipedia_2\coins.htm", line 13, in top-level template code
{% for group in records|groupby('year') %}
File "C:\Python34\lib\site-packages\jinja2\filters.py", line 712, in do_groupby
TypeError: unorderable types: str() < int()