With your 1374 version following error shows up:
Traceback (most recent call last):
File "CvScreensInterface", line 236, in showInfoScreen
File "CvInfoScreen", line 628, in showScreen
File "CvInfoScreen", line 649, in redrawContents
File "CvInfoScreen", line 689, in drawGraphTab
File "BugUtil", line 372, in logSpan
File "BugUtil", line 345, in span
TypeError: unsupported operand type(s) for -: 'float' and 'NoneType'
ERR: Python function showInfoScreen failed, module CvScreensInterface
This is an error caused by the time tracking stuff we put in. It has been fixed.