"Cannot read property 'remoteItems' of null" error when trying to list or create Organization VDC Networks

Products

• VMware Cloud Director

Issue/Introduction

Symptoms:

• The Cloud Director Tenant UI shows an error when viewing Datacenters > Networking > Networks

"Cannot read property 'remoteItems' of null" 

• The browser console shows errors similar to the following:

Unsupported REST exception OrgVdcNetworksListComponent#query#OrgVdcNetwork TypeError: "responseObject is null"
result vcd-json-rest-http.handler.ts:118
_next vendor.bundle.js:2661
next vendor.bundle.js:2661
_next vendor.bundle.js:2661
next vendor.bundle.js:2661
_next vendor.bundle.js:2661
next vendor.bundle.js:2661
notifyNext vendor.bundle.js:2661
_next vendor.bundle.js:2661
next vendor.bundle.js:2661
onLoad vendor.bundle.js:277
invokeTask vendor.bundle.js:2683
onInvokeTask vendor.bundle.js:1984
invokeTask vendor.bundle.js:2683
runTask vendor.bundle.js:2683
invokeTask vendor.bundle.js:2683
invokeTask vendor.bundle.js:2713
globalZoneAwareCallback vendor.bundle.js:2713 

• The API calls to list the networks for an Organization VDC returns a "204 No Content" response instead of the expected "200 OK".

Request:
GET "https://cloud.example.com/cloudapi/1.0.0/orgVdcNetworks?page=1&pageSize=125&filterEncoded=true&filter=(orgVdc.id==urn:vcloud:vdc:<VDC_UUID>)&sortAsc=name&links=true"
Response:
204 No Content

• The API calls to list the networks for an Organization VDC returns a "200 OK" response if the "pageSize" parameter is set to a value of "32" or less.

Request:
GET "https://cloud.example.com/cloudapi/1.0.0/orgVdcNetworks?page=1&pageSize=32&filterEncoded=true&filter=(orgVdc.id==urn:vcloud:vdc:<VDC_UUID>)&sortAsc=name&links=true"
Response:
200 OK

• Making the API call directly to a Cloud Director Cell instead of the public API address results in a valid "200 OK" response regardless of the "pageSize" parameter.

GET "https://cell.example.com/cloudapi/1.0.0/orgVdcNetworks?page=1&pageSize=125&filterEncoded=true&filter=(orgVdc.id==urn:vcloud:vdc:<VDC_UUID>)&sortAsc=name&links=true"

Response:
200 OK

Environment

VMware Cloud Director 10.x

Cause

This issue can occur if the load balancer or reverse proxy that serves the Cloud Director public API URL is interfering with the requests.
This results in the browser or API calls to the public address returning a "204 No Content" while the direct calls to the Cloud Director Cell succeeds.

Resolution

Ensure that the load balancer or reverse proxy used for the Cloud Director public addresses in front of the Cloud Director Cells is not interfering with the calls.
In particular ensure that there are no limits on header, request or response sizes that would explain why the "pageSize=32" or lower succeeds but the "pageSize=33" or higher fails.

Please work with the load balancer or reverse proxy vendor to confirm.

For an NSX Edge based load balancer the settings from the following KB article can be applied: 
Global Roles Cannot be Created or Edited in the vCloud Director HTML5 UI (67696).