While configuring the entity form in portal we were getting an error “Error in Creating Control ID, as multiple controls with the same ID were found.
After analysis we found that when a lookup attribute in Dynamics is rendered in portals, there are three separate controls . One for the ID, one for text and one for entity name. For example, if the attribute name in Dynamics is “abcd_entity”, when the control is rendered in portals it will have the mentioned below controls
a) abcd_entity_name – For text part of the lookup attribute
b) abcd_entity_id – For ID part of the lookup attribute
c) abcd_entity_entityname – For entityName of the lookup attribute
In my case the control ID “abcd_entity_name” was conflicting with the name of an existing optionset attribute in Dynamics. This was causing duplicate ID’s in the system and was this causing the error on the portal.
When we recreated the optionset attribute so as to give it a different name, the above error got resolved.