A period type is defined on the entity as Monthly, but after removing the "Period Type" attribute from displaying on the Cost Plan grid a new Cost Plan cannot be created. An error is received:
CMN-0007: Attribute 'period_type_code' is required.
Release : 16.0.x, 16.1.x
Adding a default value to the attribute will allow this to function.
1. Log into the Classic UI, and go into "Objects" under "Administration"
2. Open the "Cost Plan" Object
3. Go to "Attributes" and open the "Period Type" attribute
4. Define a "Default" value and Save
You may have to log back in for the change to take affect.