Is anyone having a problem with Excel add-ins not loading in Excel 2016, 2013, or 2010? This was not a problem with Office 2016 builds prior to build 7070, released July 12, 2016. Any workarounds?
This problem results from security patch in KB31152, released in July 2016. According to private communication with Microsoft software engineers:
"With this update, we changed the behavior of Excel so that it will not load certain file types (including .xlam) when they are untrusted. The easiest workaround is to find the add-in that is causing you trouble, right-clicking on it in Windows Explorer, and checking Unblock"
An easier approach is to simply place the add-in in a Trusted Location (in Excel, go to File > Options > Trust Center > Trust Center Settings > Trusted Locations), such as the following folder, and load it from there:
Unfortunately, Microsoft failed to clearly document this major, "breaking" change (as of this writing), leaving probably hundreds of thousands (millions?) of Excel users wondering why their add-ins are not loading. They did, however, bury some useful information about this issue in a blog post:
See http://www.jkp-ads.com/Articles/Excel-Add-ins-fail-to-load.asp about downloaded internet files.
(Does not solve my problem, but...)