It appears that a patch released this month is causing an issue with excel 2016. I don't see this patch in Altiris to deploy. Is this something that can be added?
https://support.microsoft.com/en-us/help/4011165/september-12-2017-update-for-excel-2016-kb4011165
http://myitforum.com/myitforumwp/2017/09/12/excel-security-fix-for-september-actually-requires-two-updates/
Sorry for delayed reply - this package was added to PM Import 7.2.78