Symptoms

Unable to register K2 for SharePoint.
On the "Administrative OAuth Token" portion of the registration wizard. "A network error has occurred. Unable to execute server-side operation." Redirects admin to sign into O365 again but cant.

 

Diagnoses

The issue was caused by the account running registration wizard does not have global admin permission.
 

Resolution

After log in with Global Tenant Admin account, customer was able to complete registration wizard successfully.