Manual Crop default crop x and y can contain decimal which causes invalid crop error message.

This is a problem for both the stable release and 7.x-1.x-dev.

Drupal 7.x
Manual Crop 7.x-1.x

Image Style: Manual crop (minimum crop dimensions 97x102 and maintain proportions)

Image Field on content type. Enable manual crop and select the created style.

node/add --> Upload image with dimensions of 1224 × 1632

Click crop

The selection will read: Image style: test, Selection x: 306, Selection y: 494.5, Selection width: 612, Selection height: 643

Save.

Save node --> error "The crop selection for xxxxxx.jpeg (Test image style) is invalid, please clear it or reselect.

I have created a patch and will submit.