Marc, I have replicate the described issue and I have forwarded it to our developer team for further consideration. As a workaround, I would suggest you to handle the Spreadsheet content click and verify whether an Error message window is shown. If it is - you can call the toFrom method on it:
).length > 0)
In the above example, myWindow is the id of the container of the Spreadsheet.
In addition, here is a dojo example, demonstrating the above suggestion:
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