ID 503740 - Exports fail with 'object is null' error when using Create Comp Special with multiple clips selected while HIERO_DISABLE_THUMBNAILS is active.

Problem summary
Exports fail with 'object is null' error when using Create Comp Special with multiple clips selected while HIERO_DISABLE_THUMBNAILS is active.
 
Customer reported version
nuke.12.2v10
 
Customer reported platform
n_a_windows
 
Steps to reproduce
1) From the Command Prompt/Terminal, add the HIERO_DISABLE_THUMBNAILS=True environment variable.
2) In the same Command Prompt/Terminal session, launch Nuke Studio/Hiero, then import at least 2 different clips.
3) Drag/drop the clips to the Timeline to create a Sequence.
4) Select the clips on the Timeline and right-click > Create Comp Special
5) Observe any errors given when using the Create Comp Special feature.
 
Expected behavior
The comp should be created without erroring while thumbnails are disabled.
 
Actual behavior
An error dialog appears for "object is null" when attempting to Create Comp Special with more than one clip selected while thumbnails are disabled with the HIERO_DISABLE_THUMBNAILS environment variable.

 
Workaround
There is no available workaround at this time.
 
Reproduced by Support in:
NukeStudio/Hiero 13.1v2 - Windows 10, CentOS 7
NukeStudio/Hiero 13.1v1 - Windows 10
NukeStudio/Hiero 12.1v1 - Windows 10
NukeStudio/Hiero 12.0v1 - Windows 10
NukeStudio/Hiero 11.3v1 - Windows 10, CentOS 7
 
Unable to reproduce bug in:
NukeStudio/Hiero 11.2v7 - Windows 10, CentOS 7
 
Earliest version tested
NukeStudio/Hiero 11.2v7 - This issue doesn't appear in this version and has regressed