---
url: /zoho-payments-whmcs/errors.md
description: >-
  The exact messages Zoho Payments for WHMCS shows customers and records in the
  Gateway Log — license-inactive fallbacks, plus OAuth and webhook failure
  conditions.
---

# Error reference

This page lists the messages you may see from Zoho Payments and what each one means. The gateway
records its activity in the **Gateway Log** (**Utilities → Logs → Gateway Log**); check there first
when diagnosing a problem.

## License messages

When the license is **inactive**, the gateway fails safe. New payments are blocked, but any payment
already made at Zoho is still recorded.

| Where | Message | Meaning |
| --- | --- | --- |
| Customer, invoice page | *Online payment is temporarily unavailable. Please contact us to complete your order.* | The license is inactive, so a **new** payment cannot be started. |
| Gateway Log | *Payment blocked - license not active* | Recorded when a new payment is blocked (at most once an hour). |
| Gateway Log | *License Not Active - proceeding to verify/record payment* | A payment already made at Zoho is being **verified and recorded** even though the license is inactive — nothing is lost. |

To clear these, renew or re-enter your key — see [Licensing](/zoho-payments-whmcs/licensing).

## OAuth failure conditions

OAuth errors appear in the Gateway Log when the gateway can't authorise with Zoho or refresh its
access token. Common causes:

* **Invalid Client ID or Client Secret** — the credentials don't match the application in the Zoho
  Developer Console.
* **Redirect URI not registered** — the redirect URI used to generate the token isn't listed on the
  application, so authorisation is refused.
* **Revoked or stale refresh token** — the stored refresh token no longer works and must be
  regenerated with the **"Click Here to Generate Token"** helper link.
* **Wrong data centre** — the credentials belong to a different Zoho data centre than **Data
  Center** is set to.

See [Troubleshooting → OAuth token errors](/zoho-payments-whmcs/troubleshooting#oauth-token-errors).

## Webhook failure conditions

Webhook events for Payment Links are rejected — and logged in the Gateway Log — when they can't be
trusted or delivered:

* **Signature mismatch** — the **Webhook Secret** in Zoho doesn't match the one in the gateway
  config, so the HMAC-SHA256 signature check fails and the event is rejected.
* **Unreachable endpoint** — the webhook URL isn't correct or the site isn't serving valid HTTPS,
  so Zoho can't deliver the event.
* **Verification failure** — the referenced payment can't be confirmed against the Zoho API, so the
  invoice is not marked paid.

See [Troubleshooting → Webhooks not processing](/zoho-payments-whmcs/troubleshooting#webhooks-not-processing).

## Related pages

* [Troubleshooting](/zoho-payments-whmcs/troubleshooting) — step-by-step fixes
* [Licensing](/zoho-payments-whmcs/licensing) — what the license gates and the fallback behaviour
* [Configuration](/zoho-payments-whmcs/configuration) — the fields these errors point to