Hello @JoanR81 ,
There's likely a permissions or compliance-hold on that particular contact. You can do one of the following:
Or, if you're wishing to keep engagement history:
William - I have the same problem. While your solution seems to fix this, it would be nice to know why there would be a permissions or compliance-hold preventing a simple email change.
"There's a multitude of ways to engage your audience through us using your social platforms - via ads, social post metrics, email links, and more! " - WillSee Article
"Target your most engaged contacts by creating a segment. Create a special offer or show your appreciation!" - CaitlinSee Article
"Greet new contacts with one or more automated Welcome Emails depending on their interests or your business goals." - NickSee Article