I am still facing the youtube 500 internal server error. I am facing the issue since last past week. To solve the error, I tried various methods mentioned on the Internet. One of the solutions which worked partially was -
Troubleshoot 1: Let the YouTube Team To Fix
Troubleshoot-2: Refresh the YouTube Page
Troubleshoot-3: Use Chrome as Default User and Clear Cache
Troubleshoot-4: Contact YouTube Support Team