Signals Notebook: Importing Compounds into Materials Library using API may respond with: The content did not contain a single chemical object

Details: While importing compounds into a Materials Library, you may receive the following message:

Failed to get cdd properties (445): 
{"status":445,"title":"The content did not contain a single chemical object","detail":"The content did not contain a single chemical object"}'

A similar message can be seen if trying to create the same compounds through the UI:

The molecules need to be grouped into a single group using the following tool:

This will allow you to save the compound. You will need to do this in for each compound imported through the API as well.