@chaley, with this calibre release there is a different problem:
Spoiler:
Traceback (most recent call last):
File "site-packages\calibre\utils\formatter.py", line 524, in safe_format
File "site-packages\calibre\utils\formatter.py", line 495, in evaluate
File "string.py", line 543, in vformat
File "string.py", line 576, in _vformat
File "site-packages\calibre\utils\formatter.py", line 480, in format_field
File "site-packages\calibre\utils\formatter_functions.py", line 128, in eval_
TypeError: evaluate() takes exactly 5 arguments (7 given)