The RealPlayer functionality, Downloading & Recording, has compatibility issues with Flash Player 11.3. If RealPlayer is installed, Flash Player content does not appear. YouTube provides an error message when you try to watch a video.
As a workaround, do the following:
An outdated graphic card or driver can cause this issue.
Do the following:
- Disable hardware acceleration. For more details, see Disable Flash Player hardware acceleration.
- Verify whether the video works without any issues in the full screen mode.
- If Flash Player doesn't crash, update the graphic card or driver. Then, enable hardware acceleration.
- If Flash Player crashes, note that in Adobe Bugbase.
If the problem still persists, record it in Adobe Bugbase.
Provide the following:
- Direct link to the page that resulted in the crash
- Description about the operation you performed which resulted in the crash
- Firefox crash logs
For more details, see Report a Flash Player crash.
To install a previous version of Flash Player, see How do I revert to a previous version of Flash Player.