Website encountered an unexpected error after following password reset link

Hello,

After following a password reset link I get unexpected error message. When I check the log messages I see this error:

EntityMetadataWrapperException: Invalid data value "" given for wrapper chain user:. in EntityDrupalWrapper->set() (line 757 of /var/www/mysite/sites/all/modules/entity/includes/entity.wrapper.inc).

Any ideas?