This errors happens when 1) your vRO server is configured with vRA authentication and 2) vCenter endpoint has been registered in vRO in 'session-per-user' mode. In this scenario, calls from vRO scripting code to vCenter API will try to authenticate with a CSP token issued on behalf of the user currently logged in vRO, and will fail because currently vCenter does not understand/cannot handle CSP tokens.
To resolve this error, you should either change your vRO server authentication provider from vRealize to vSphere, or register vCenter endpoint in vRO using shared session mode. Both options have some drawbacks. Hopefully at some point in the future all VMware products will be able to use a common authentication solution.