ID 370758 - Qt 5: Importomatic throws an exception when changing the versions of assets

Problem summary:

When changing the version of assets...

Steps to reproduce:

• Load the attached scene file
• View and Edit the LookFileBake node
• Write the Look File.When promted via PyMock make sure the asset version is 1, then click accept
• Write the Look File again. This time click the Version Up button and then accept.
• Now View and Edit the Importomatic Node
• Click the droip down on the default/Asset and change from 1 to 2.

Expected behaviour:

Asset versions up with no errors

Actual behaviour:

The asset does not version up and the following exception is raised.

[ERROR python.root]: A TypeError occurred in "Editor.py": Fields arg: all keys/values must be strings.    Traceback (most recent call last):        File "plugins\Resources\Core\SuperTools\Importomatic\Importomatic17\Editor.py", line 874, in __popupVersionsItemChosen    TypeError: Fields arg: all keys/values must be strings.

Tested versions/platforms:

• 3.1dev#77 - Unaffected
• 3.1dev#82 - Affected

Customer version/platform:

• 3.1v1 #10014

• 3.1dev #654