Lots of Past-Due Actions

Folks:

I have an error message: “Action Scheduler:?94?past-due actions?found; something may be wrong.?Read documentation ?”

When I click on the link to see my past-due actions, it tells me that I have 94 past-due actions and 30,958 failed actions.

It also persistently says “Action Scheduler migration in progress. The list of scheduled actions may be incomplete.”

And when I try to see what events have happened: “There was a problem spawning a call to the WP-Cron system on your site. This means WP-Cron events on your site may not work. The problem was:

Unexpected HTTP response code: 404“

ALSO, I have no Action Scheduler option in my WordPress Tools menu.

Can anyone help me troubleshoot this?

The page I need help with: [log in to see the link]