"Unhandled exception" with "Youtube Zero Annotations"

Hello everyone,

an unhandled exception occurs permanent if the firefox addon “Youtube Zero Annotations” is enabled.

Message text:

Unhandled exception

TypeError: YTPlayer is null

Stack trace:
YTPlayerAPI@https://www.mydomain.com/tt-rss/#f=3&c=0:9:4
@https://www.mydomain.com/tt-rss/#f=3&c=0:5:33

Here you go. You can report the issue to the add-on’s developer.