Pressing the ESC key cancels the test. This is not really an error, more of a notification why the test ended. In some rare cases this may also be caused by an unknown error with the test workload. If you did not cancel the run, contact our support for assistance to figure out what exactly did cause the run to end prematurely. Include a result file with your email if possible. Automatically saved result files can be found in Documents/3DMark/ folder.