On mediawiki.org in both Chrome and FF.
Edit any page with VE, either logged in or not. Note that you get the beta warning.
Save your edit. Edit the page again.
See the beta warning again.
After one new VE edit, the user should never see the beta warning again. This is controlled by setting a cookie in the browser. No betawarning cookie is being set now.
Version: unspecified
Severity: major