Thank you so much
Hello,
Thank you for contacting us.
As indicated in the error call stack, the content part type that you are using for your part is not valid:
part = contentPackage.createPart("Number Test Content")
When working with an OffScreenEditor you must use a "Raw Content" part:
part = contentPackage.createPart("Raw Content")
Best regards,
Gwenaëlle
Sid20245666
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