Custom UI Runtime Error in iCloud Add-in

Outlook Add-In

This has stopped working this week on my SurfacePro Laptop running Windows 10 and Office 365 after no trouble at all.....this is the message I get when I open outlook

Custom UI Runtime Error in iCloud Add-in

Error found in Custom UI XML of "iCloud Outlook Add In"

Line 3

Column 8

Error Code 0x80004005

Failed to find Office control ID

ID: Tab folder

OK or OK to all

Please don't tell me to just disable the add-in, I sync my account across my iPhone, iPad, Mac and three windows PC's so that is not an option.