The "ResourceAccess" exception in Pega usually indicates that the service REST API is failing due to some kind of authentication or authorization issue.
One possible cause of the issue could be the authentication token used by the external application to access the REST API. If the token is expired or invalid, Pega may reject the request with a ResourceAccess exception.
To troubleshoot the issue, you can try the following steps:
Check the authentication configuration of the service REST API in Pega. Ensure that the authentication type is set correctly and the authentication mechanism is working properly.
Check the logs in Pega to see if there are any error messages related to the ResourceAccess exception. The logs may provide more details about the cause of the issue.
Verify the authentication token being used by the external application. Ensure that the token is valid and not expired. You can try generating a new token and see if that resolves the issue.
Check if there are any firewall or network issues that may be preventing the external application from accessing the service REST API.
If the issue persists, you may need to engage Pega support for further assistance. They can help you troubleshoot the issue and provide a resolution.