Hello, @lidiia_deliaiev and
Welcome to the Canvas Community! You probably don't realize that you've posted this question in a global forum where people gather to exchange their ideas and practices around using Canvas software. The members participating here don't have access to any course content or materials other than their own and won't be able to answer questions specific to your course.
That said, we can provide some general advice. It's possible that you're not able to see discussion content because of an issue with an out-of-date/unsupported browser, so please try these troubleshooting steps:
You'll need to contact the instructor directly for information about the webinar. The quickest way to do that is by sending a message through the Canvas Inbox, as described in How do I send a message to a user in a course in the Inbox as a student?
Last, if the browser/cache-clearing instructions don't resolve the problem with disappearing content, contact Canvas Support. General instructions are in How do I get help with Canvas as a student? but your school's support setup might vary somewhat, in which case ask your local IT Department for additional troubleshooting assistance.
Good luck!
This discussion post is outdated and has been archived. Please use the Community question forums and official documentation for the most current and accurate information.