To fix your issue, please follow these steps.
1. Open RealPlayer.
2. Click the RealPlayer logo, then Preferences.
3. In the Category pane, select Hardware.
- Under Video Card Compatibility, move the slider bar to Most reliable.
- Click OK twice to save the changes.
- Close out of RealPlayer, restart it.
If this doesn't help, move move the slider bar to Best Performance and restart it.