I upgraded from Excel 2011 to Office 365 subscription for use on iMac running Sierra 10.13.2.
For my excel spreadsheets, whereas previous 2011 version with hyperlinks opening jpg images in the hyperlink function was no problem
In the latest version, I get the message additional permissions required then I have to grant access having looked through lists of jpg images. Please fix this UPGRADED' version of excel for mac.
For me this has been an ongoing issue with Excel for Mac 2016. 2011 worked fine but upgrading to 2016 it stopped working. Reported many many times but no real fix.
For me it is slightly intermittent in that it fails 99% of the time but has occasionally had brief periods where it works.