The result for Benchmarking package you have described is strange. In cases we have seen so far even if errors occurred during test run files in Results folder contained data.
If errors are thrown during test execution it means that test run was not successful. If errors occur during first test scenario it is a strong indication that something was not configured correctly. To answer your question - the Error level should be zero for a successful run.
The reason why the jmeter.qvd was not generated might be that your result files were empty.
The jMeter.log file contains only log which are specific to jMeter they are not the test results.
Based on your description I'm not able to pin point what might be cause of the problem. The suggestion is to try to set up the tests again following steps described in documentation.