Error using table 370 Excel Buffer for import data

Hi,

I'm on NAV 2015 8.0.40262.0 (HF5).
I'm getting the following error:

Microsoft Dynamics NAV

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A call to Microsoft.Dynamics.Nav.OpenXml.Spreadsheet.WorkbookReader.Open failed with this message: C:\Data.xlsx

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OK

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Last month it worked fine. Perhaps an Office 365 update messed it up?

Seems it's a returning error. Saw in NAV 2013 R2 there it was bug then.

Anybody any idea how to fix it?
Or can only Microsoft deliver the solution?

Thanks in advance!