1. Confirm that the installed package matches the product and version supplied with your order. Record the WHMCS URL and deployment details requested by the licensing instructions.
2. Open the Domain Nexus addon settings. If the edition exposes Licence key, enter the issued value carefully and save it.
3. Open the module's licence panel and select Check now when shown. Read the full returned status rather than assuming that saving a field completed validation.
4. Reopen a protected module page and confirm the expected services are available to the intended administrator role.

Store the key as a credential. Share only a masked reference and order number in routine support conversations. Staff who need to configure DNS providers do not automatically need access to licensing credentials.

First check the exact error: an invalid key, a deployment mismatch and an unreachable licensing service require different remedies. Confirm the server can make outbound HTTPS connections, its clock is correct and its certificate trust store is current. A proxy, firewall or incorrect system time can prevent a valid installation from completing validation.

If you moved WHMCS to another domain, address or server, follow the purchased licence's reissue or migration procedure. Copying the old configuration does not establish that the new installation is licensed. Do not repeatedly rotate unrelated provider API tokens while troubleshooting a licence error.

Track licence renewal and update eligibility alongside your WHMCS maintenance schedule. Before an upgrade, back up settings and the protected secrets directory. An expired update entitlement, failed network check and expired service licence can have different consequences, so use the actual status displayed and your purchase terms.

If the problem remains, provide us with the product edition, version, installation URL, time of the failed check and its message. Do not send the encryption master key, connector-signing private key or a database export containing provider credentials. These are separate from the information normally needed to diagnose licensing.

• Install Domain Nexus in WHMCS and initialise its secure storage
• Upgrade Domain Nexus while preserving keys, settings and customer data
• Keep Domain Nexus jobs, scheduled DNS changes and reconciliation running
• Prepare HostBill domain contact and registry fields for current API validation