Succession Plans - Error when adding a candidate to a Talent Pool

Summary:

We would like to avoid getting the error "Error response during RestAction" when adding a candidate to a talent pool

Content (please ensure you mask any confidential information):

Hi,

When we go into an existing Succession Plan as manager or administrator, and select one or more candidates to add to a talent pool, we get this error:

this happens only to owners with only custom roles;

while another owner with both custom roles (including super user) and seeded roles (Human Resource Help Desk Administrator, Human Resource Help Desk Agent, Human Resource Help Desk Manager, Human Resource Specialist Data Role, Knowledge Analyst, Knowledge Author HCM, Knowledge Manager, Next Gen Human Resource Help Desk Administrator, Next Gen Human Resource Help Desk Manager, Next Gen Human Resource Help Desk User) is able to add the candidates without getting this error.