Views:

Applies to Product - Dynamics 365 Field Service

What’s happening?
The "Multiselect Lookup Control" is not available for selection from the custom control options when customizing a field
 
Reason:
The "Multiselect Lookup Control" requires Field Service to be installed in the environment 
 
Resolution:
To resolve this, Field Service must be installed in the environment. Alternately, a custom control could be created to accomplish similar behavior.