"'NoneType' object is not subscriptable" error when performing NSXV to NSXT migration

Products

• VMware Cloud Director

Issue/Introduction

• Performing NSXV to NSXT migration using VMware NSX Migration for VMware Cloud Director fails.
• During migration the following error is seen in the VMware NSX Migration for VMware Cloud Director logs, <NSX_MIGRATION_INSTALL_DIRECTORY>\logs\<VCD_URL>\Migration\<ORG_NAME>-VCD-NSX-Migrator-Main-DD-MM-YYYY-HH-MM-SS.log:

2023-08-08 13:25:50,009 [nsxtOperations]:[updateEdgeTransportNodes]:442 [DEBUG] [<ORG_VDC_NAME>] | Updating Edge Transport Node <NSX_EDGE_NAME>
2023-08-08 13:25:50,014 [connectionpool]:[_new_conn]:971 [DEBUG] [<ORG_VDC_NAME>] | Starting new HTTPS connection (1): <VC_URL>:443
2023-08-08 13:25:50,127 [connectionpool]:[_make_request]:452 [DEBUG] [<ORG_VDC_NAME>] | https://<VC_URL>::443 "GET /mob/?moid=<ESXI_CLUSTER_MOREF> HTTP/1.1" 200 None
2023-08-08 13:25:50,139 [vcenterApis]:[mobsApi]:280 [DEBUG] [201224-Silver-Resv-01] | Successfully fetched domain - '<ESXI_CLUSTER_MOREF>' information from vCenter
2023-08-08 13:25:50,149 [vcdNSXMigrator]:[run]:1050 [DEBUG] [MainThread] | Traceback (most recent call last):
 File "src\vcdNSXMigrator.py", line 1030, in run
 File "src\vcdNSXMigrator.py", line 885, in runBridging
 File "src\core\nsxt\nsxtOperations.py", line 1122, in configureNSXTBridging
 File "src\core\vcd\vcdValidations.py", line 150, in wrapped
 File "src\core\nsxt\nsxtOperations.py", line 64, in inner
 File "src\core\nsxt\nsxtOperations.py", line 53, in inner
 File "src\core\nsxt\nsxtOperations.py", line 465, in updateEdgeTransportNodes
TypeError: 'NoneType' object is not subscriptable

Environment

VMware Cloud Director 10.x

Cause

This issue will occur if the correct NSX bridging edge is not returned in the response to the vCenter API GET to the vCenter Server Managed Object Browser, GET https://<VC_URL>::443/mob/?moid=<ESXI_CLUSTER_MOREF>.

Resolution

If the NSX Bridging Edges are located in a different ESXi host cluster in vSphere than the Source VMs to be migrated, move the NSX Bridging Edges to the same ESXi host cluster and repeat the migration attempt.