There are a couple of workarounds to choose available:
1. At the bottom of the Welcome Screen, clearing the checkbox "Show again next time" will prevent the Welcome Screen from appearing the next time you login. Note this is per browser only, so if you have multiple users from multiple desktops, they all will have to perform this action. If the cookies are cleared, you will also have to repeat this action.
2. The Welcome Screen can be skipped for all users by commenting out the "introscope.apmserver.ui.welcome.url" property in the IntroscopeEnterpriseManager.properties file
3. Change the default Welcome Screen to something that does not contain the youtube videos that are blocked by a company proxy server. Change "introscope.apmserver.ui.welcome.url" property from "HID_Welcome_to_CA_APM" to "HID_BLUE_BOX_PAGE"