Using IEDriver in Selenium may lead to some security issues like Unexpected error launching Internet Explorer. Protected Mode settings are not the same for all zones. Enable Protected Mode must be set to the same value (enabled or disabled) for all zones. (WARNING: The server did not provide any stacktrace information)
The Protected mode settings may be different,these are managed by administrator and we are not authorized to change these settings,i n these cases adding capabilities to the driver instance may overcome these issues.
Below is the code.
DesiredCapabilities caps = DesiredCapabilities.internetExplorer();
WebDriver driver = new InternetExplorerDriver(caps);
More about IE Protected Mode Click here