https://helpx.adobe.com/flash-player.html
See our comments which appear below, about this page, if you need additional guidance or help.
Step 1. You will see this. Click the check now button.
A utility will run and it will tell you if you have flash installed or not, and whether it is working. As an example,
you might see this if you don’t have flash installed or enabled. Click on the Red - sign
Step 2. If necessary, as directed above, install Flash by clicking the blue link in Step 2.
Step 3. These step should be straight forward. Run the installer and complete the install.
Step 4. After installing Flash, it must be enabled within your browser to work correctly. Click the
appropriate link in this list to read and follow the instructions to enable Flash
Step 5. Once you have completed Step 4, you will now confirm that it is installed. In step 5 you
will see a small animation (image below). If the clouds are moving then you know that flash is working.
After completing the 5 steps above and confirming that flash is work correctly, go back to the GL icon and click it.
It will open this “Table of Contents” screen.
When you click on the song name in the left hand column, the flash file (.swf) should then appear in your browser
and look something like this. If you do, you are done and can now begin to use GL.
Clicking the Audio OFF text will toggle the audio on and off. Next click the Red numbers above the Audio Off
text toggles you between different segments or lessons for this song.
If you don’t see the above and instead see a blank screen or another program beside your browser which opens this
screen or tries to open this screen that is a problem. In that case you’ll next need to change your file associations.
Here is how you do that:
Changing File Associations in Mac (OSx)
https://www.macrumors.com/how-to/how-to-manage-file-associations-in-macos/
Changing File Associations in Windows
https://www.thewindowsclub.com/change-file-associations-windows
Lastly, some browser are more difficult than others to configure to run Adobe Flash. If you are struggling with one,
you might consider switching and trying a different browser.