PKS cluster creation in NSX-T fails with error cannot unmarshal string into Go struct field

Products

• VMware Tanzu Kubernetes Grid Integrated Edition

Issue/Introduction

Symptoms:
Cluster creation using the pks cli fails with error message

pks create-cluster oom --external-hostname outofmemory --plan small -n 2

Error: Error creating NSX-T cluster network `pks-903644ae-3c20-4ac7-a331-aee8b117931a`: json: cannot unmarshal string into Go struct field APIError.error_code of type int64

Environment

Cause

The principal identity with superuser permissions configured under NSX Manager Super User Principal Identity Certificate is missing under Principal Identities. This is how to see these options:
Go to PKS Tile, select Networking, select NSX Manager Super User Principal Identity Certificate. 
Go to NSX-T Manager, select System, select Users, select Principal Identities.

In this scenario NSX-T manager returns a response which can not be decoded by PKS CLI.

Resolution

Re-register the NSX Manager's super user principal identity certificate using these instructions.