Could not complete the operation. One or more parameter values are not valid. Outlook 2010

Posted by Andrew Denner on May 09, 2012 · 1 min read

Jimi Hendrix's address book

I ran into an odd error when trying to send email from our newly configured Office 365 hosted exchange.  When sending email to people who were already in my auto complete address book I would receive the message “Can not complete the operation” a fellow user also recieved the error “Could not complete the operation. One or more parameter values are not valid.”

It turns out that this is a corruption in the frequently used email address cache and can be cured by deleting the cache by going to File/Tools/Options/Mail and choosing clear autocomplete