GMIC doesn't work when viewing only a portion of the image in the viewer

[Shrinks99]

Describe the bug
When I use any GMIC node in Natron if I am zoomed in and viewing only part of the image it does not render and results in an error.

To Reproduce
Steps to reproduce the behavior:

1. Insert a GMIC node into the nodegraph (I am using the textured glass node right now but this has happened with all other nodes I've tried)
2. Zoom in so the viewer is not viewing the entire image
3. Enable the GMIC node or change a setting to cause it to re-render
4. See error
5. Zoom out so entire image is visible and try to render it again

Expected behavior
The GMIC node's effect should work when zoomed in

Desktop (please complete the following information):

• OS: Windows 10
• Version: Natron 2.3.14
• GPU: Nvidia GTX 970 (I currently have OpenGL disabled)
• CPU: Intel i7 5520K