My org just switched to Lightning and a user says he can not set himself as the Owner of an Opportunity. He can set the owner to someone else (a user with a standard sales profile) but then he can't switch it back to himself. Others can set the owner to him as well.
When he tries to set the user to himself from a different owner, it says -
"You don’t have permission to take that action on this record or related records. For help, contact your Salesforce admin."
This person's profile has all the same read/write permissions on Opportunities as the other user's profile. I don't know what I should be looking into here. Is there a different restriction for assigning something to yourself or is it just something permission related I'm missing?