Exchange 2016 – Error 500 when running Hybrid wizard

While trying to run the Hybrid wizard in Exchange 2016 (the link at the bottom left of the Exchange Admin Centre) I get a HTTP 500 error after logging in with my Office 365 credentials:

It may be just coincidence but I believe I was able to resolve this by installing the latest cumulative update.  I understand that the on-premise Exchange server version can’t be more than 2 CUs out of date for it to work, and this server was.  After installing CU14 the error went away.