Unable to login to NSX Manager Web UI with admin account, error "The username/password combination is incorrect or the account specified has been locked."

Products

• VMware NSX

Issue/Introduction

• Deploying a new NSX Manager appliance through the built-in vCenter plugin
• Unable to connect another appliance to NSX via API.
• Unable to login to NSX Manager Web UI with admin account, error: 
  Your login attempt was not successful.
The username/password combination is incorrect or the account specified has been locked.

Environment

VMware vSphere 8.x
VMware NSX 4.x

Cause

NSX appliances that were deployed via the built-in vSphere plugin can only be managed via the plugin.

To confirm if you are using the vSphere Plugin:

• Go to the vSphere Client hamburger menu (The Icon with 3 stacked lines in the upper left of the vSphere Client)
• Check the drop down menu for an "NSX" Object
• If this exists and loads NSX inside the vSphere client frame, then you are using the vSphere NSX plug-in and need to redeploy NSX
• If NSX is deployed as a standard OVA Appliance image in the vSphere client and registered with vCenter as a Compute Manager this option will not be present.

Resolution

Re-deploy NSX via the standard process to deploy an OVA in vCenter and per NSX installation guide: Install NSX Manager and Available Appliances
Once the deployment is complete, admin login to the NSX Web UI will be successful.