ID 362708 - Resizing/Moving the Clip view window causes a hard crash.

Problem summary
Resizing/Moving the Clip view window causes a hard crash.

Customer reported version
modo.12.1v1

Customer reported platform
windows10

Steps to reproduce
1) Open Modo.
2) Hold "Ctrl" and click the cube primitive to create a unit cube.
3) Select the cube and press "m" to create a material. Name the material and click "Ok.
4) Select the "Shading" tab in the item bin in the top right.
5) Select the material created in step 3.
6) Click "add layer,"  then select Image Map>Load Image and load an image.
7) Select the Image in the shader tree.
8) Under "Image Map" click the image to expand the clip browser.
9) Click the edge of the image browser and drag it.
Result: Modo will crash.

Workaround
Unknown. 

Reproduced by support
This bug has been reproduced in:
12.1v2 - Windows 10, OSX 10.13.5
12.1v1 - Windows 10, OSX 10.13.5

Unable to reproduce bug in:
12.0v1 - Windows 10, OSX 10.13.5

Earliest version tested
12.0v1 - Windows 10, OSX 10.13.5 - This issue no longer appears in this version and has regressed
Expected behaviour
The clip browser should move or resize.

Actual behaviour
Modo crashes.