trying to save a contact but got the error:

Error saving data: Cannot have more than one contact with email address <email address>

can’t find the email address in ‘all contacts’. searching the contact with the email address returns 0 (zero) result.

switch to older version (link on bottom of the page). go to contacts page. the contact you couldn’t previously find is now on the list. do whatever editing you need to do. switch back to newer version. the email address is now there.