If you receive an error message of a Fatal Render Error, make sure this message isn't telling you a solution for the problem. If not, click on "yes" and copy the error report number and submit a Support Request on the "Client Crash" subtype, informing this number so our support team can investigate the problem.
If your game closes without an error message, contact our support giving as many details as possible, such as if you are doing something specific when this happens or if it happens in all regions. If this happens on an Android device, check this article before contacting our support.