The error "Request failed with status code 413" in Mendix indicates that the server rejected the request because the payload (i.e., the file being uploaded) exceeded the maximum allowed size.
To resolve this issue, you can try the following steps:
Check the maximum file size allowed for file uploads in the Mendix project settings. If the maximum file size is less than the size of the file you are trying to upload, increase the maximum file size allowed for file uploads.
Check the maximum file size allowed in the server configuration. If the maximum file size is less than the size of the file you are trying to upload, increase the maximum file size allowed for file uploads in the server configuration.
If you are uploading the file using a REST API, check the maximum payload size allowed in the API endpoint configuration. If the maximum payload size is less than the size of the file you are trying to upload, increase the maximum payload size allowed in the API endpoint configuration.
Check if there is any network-related issue or firewall blocking the upload. Try uploading the file using a different network or firewall to rule out any network or firewall issues.
If you have access to the server logs, check the logs to see if they provide any additional information about the cause of the error.
If none of these steps resolve the issue, you may want to reach out to Mendix support or your server administrator for further assistance.