Problem
Prompted with the error from previewing an invoice in open orders:
Print configuration cannot be viewed from threaded window. Is expected. Not an error
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Internal thread prevents Print Dialog to be shown. External component has thrown an exception.
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Internal thread prevents Print Dialog to be shown. External component has thrown an exception.
Cause
This is caused when the preview is shown inside a print job. This is not an error as the printer settings cannot be accessed while in preview from the Open Orders screen
Solution
There is no solution for this as this is not a bug rather a warning that the settings cannot be accessed.
If you need to select a printer do so when it prompts before the preview is opened.