Thanks for everyone who tried to help me. Mystery Problem solved. It was (weird) personalization setting that was causing this issue, since the users had only one assignment block in Account OVP
Somehow iv_ref is getting ref to the class CL_CRM_GENIL_CONTAINER_OBJECT instead of CL_CRM_GENIL_CONTAINER_OBJLIST. Requested user to reset to defaults as shown in the figure everything worked great after that no BSP error. Thanks again everyone. I have to sleep now.
