Ajax TruClient scripts do not run in Load Mode due to McAfee Anti Virus
Issue: Newer versions of McAfee Anti-virus may cause network hook collision with the Ajax TruClient for IE protocol. You may experience unexpected behavior during load. For example, some of your Vusers may stop running. As a result, an error message will appear in the Controller >Scenario Status > Errors pane and the Vuser status displays as Failed.
To resolve this you must disable McAfee.