Why do I get an "Access denied or application not found" (status_code 210) error when using the /createMessage API?

status_code: 210 with "Access denied or application not found" from /createMessage means the request was parsed and authenticated, but Pushwoosh refused to act on the application you specified. HTTP status is still 200 — always parse status_code.

Check these causes in order:

1. The token has no access to that project. In the Pushwoosh Control Panel go to Settings → API Access, open the token you use, and make sure the project whose Application Code you pass in the application parameter is selected in the project list (or use "Grant access to all projects"). Save and retry.
2. The application parameter is missing or wrong. It must be the Application Code (e.g. XXXXX-XXXXX) of a project inside the same account as the token.
3. No platform is configured for the project. A project with no configured platform cannot accept a message request — configure at least one platform in Configure platforms.
4. The requested feature is not available on your plan (for example sending to a users list). Contact support to confirm your account's feature set.

210 is not retryable: the same request will always return 210 until the underlying configuration is fixed.