I want to download the new Office for Mac 2016. Will all my older (2008) office files automatically convert to the new version ok? Including PowerPoint embedded videos and transitions, etc? Thanks.

Office 2016 will read & write the files created by previous Office versions. That said, there seem to be numerous problems with office 2016 on the Mac, so you might want to hold off until they're sorted.

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Cheers,
Paul Edstein
[Fmr MS MVP - Word]