Office 365 users: beware Outlook’s mysterious Not Implemented error

Outlook broke on my laptop the other day. Well, it still received mail, but many operations threw up an error, “Not Implemented”.

It was particularly annoying that the error affected sending emails, but the error dialog only showed when I tried to force a send and receive. Therefore, emails were stuck in the outbox with no notification.

This error can indicate a corrupt installation, but in my case it was simply an Office 365 mess-up. In particular, the problem was connected to a an automatic upgrade from Office 2013 Professional Plus to Office 2016 Pro Plus, for users on Office 365 E3 subscriptions.

Users are meant to see an upgrade notification before this occurs. I don’t recall seeing this, but it is possible. I suspect my problem was related to an issue that caused Microsoft to pause “Microsoft-initiated upgrades” on May 9 2016. Perhaps I clicked the upgrade offer back in May and had forgotten about it.

As far as I was concerned, Office 2013 had not in fact been upgraded. I use Office applications by clicking shortcuts on the taskbar, and these were still for Office 2013. I had not seen any notification of an upgrade completing.

When I got the error though, I looked a little more deeply and found that I had both Office 2013 and Office 2016 (the latter described as Microsoft Office 365 Pro Plus) installed. Control Panel – Programs and Features also showed that both were installed on 16th June 2016, two days after “Microsoft-initiated upgrades resumed for computers that had downloaded the Office 2016 upgrade files prior to May 9 2016.”

The fix was simple. Remove Office 2013. This removed my taskbar shortcuts, but I could then reinstate them with the 2016 versions and everything worked.

Just a small issue perhaps; but certain aspects of this are disappointing.

One is the incorrect error message. I know raising the right error message is challenging, but it is important.

Second, I doubt the automatic upgrade is meant to leave both versions in place. Why cannot Microsoft figure out how to remove the old version, install the new one, and even preserve my taskbar shortcuts with their equivalent upgraded versions?