This appears different from the other reports of this error that have reportedly been fixed. The images were imported via the migrate module, so they have not yet gotten any settings. It looks like imagecrop is not correctly setting the crop area according to the automatic settings I have set.

Here's what dpm(func_get_args()); in that function outputs:

0 (Object) stdClass
1 (String, 0 characters )
2 (String, 2 characters ) 29
3 (Integer) 146
4 (Integer) 82

A crop has not been defined for the image, so it should be automatically cropping it. Obviously, parameters 1 and 2 should be numbers, not strings, so something is amiss there, but secondly, I can't see why parameter 1 should ever be empty. Something is definitely broken in the calculation of those values.