After creating a relationship contacts one-to-many with opportunities (what i want to do is include in each opportunity a unique refference contact in the customer size, which works perfectly, but when i go to contacts, the subpanel is disappeared, and instead of it, I get:

LayoutManager: Class not found:SugarWidgetSubPanelContactLink

What should I do there to restore it? how can i roll it back and begin again?. I already deleted the vardef, and
/opt/bitnami/apps/sugarcrm/htdocs/custom/Extension/modules/relationships/relationships (metadata) rebuilt. but still getting the message

should i replace some of the directories of sugar from a fresh distribution?