Conflict with WordPress v5.5

Yes, latest update breaks classic editor

Same here ??

Yes, I confirm, the same problem with my blogs
Thanks for your support

I confirm, too.

Same here. It can be resolved temporarily by installing the jQuery Migrate Helper. https://www.ads-software.com/plugins/enable-jquery-migrate-helper/

Yes. The symptom for me was not being able to toggle Visual/Text editor. Installed the jQuery Migrate Helper and it showed this warning (5 times):

/wp-content/plugins/wp-inject/wpdf-editor-js.js: jQuery.fn.live() is deprecated

When I deactivated this plugin, the problem was resolved.

Developer, please address this problem.

This problem still exists, and jQuery Migrate Helper certainly shouldn’t be a permanent solution – so we really need a new version that works with the Classic Editor without requiring jQuery Migrate Helper. It might just be a case of getting rid of the call to jQuery.fn.live().