Excel Online – “Sorry, we couldn’t open this link. The link address may be invalid, or you may not have permission to open it.”

I have found that when you enter a hyperlink into Excel Online, open in the Excel Rich Client, Save, and then re-open in Excel Online, the hyperlinks are updated and subsequently broken. So if you enter a hyperlink (in Excel Online): https://contoso.sharepoint.com/Documents/2017 Financials.xlsx?d=<guid> it will be changed to a relative link:  2017 Financials.xlsx?d=<guid> and you will see…

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