email to contacts-error-not registered interface? (use to work?)

[J Mazz]

It will not allow me to send email to my contact groups. When I click send -
it states "interface not registered". It had worked for over a year.

 

[Russ Valentine [MVP-Outlook]]

State your question more clearly. Include information such as what you are
doing, what you mean by "Contact groups" (Outlook has no such term), changes
made before you lost functionality, and what functionality you lost. Outlook
version and mail transport would be necessary too. Remember. This is a
newsgroup. You must state issues clearly and not make us guess.