New post title and Yoast seo plugin doesn't load

[cartseg]

after updating to wordpress 5.5 I cannot add a new post:
​https://www...../wp-admin/post-new.php
doesn't show the post title and some other sections are not loaded (e.g Yoast seo).

Errors:

admin.js?ver=1.1:99 Uncaught TypeError: $(...).live is not a function
    at HTMLDocument.<anonymous> (admin.js?ver=1.1:99)
    at i (jquery.js?ver=1.12.4-wp:2)
    at Object.fireWith [as resolveWith] (jquery.js?ver=1.12.4-wp:2)
    at Function.ready (jquery.js?ver=1.12.4-wp:2)
    at HTMLDocument.J (jquery.js?ver=1.12.4-wp:2)
post-edit-1470.js:1 Uncaught TypeError: Cannot read property 'loadFacebookPreviewData' of null
    at HTMLDocument.<anonymous> (post-edit-1470.js:1)
post-edit-1470.js:1 Uncaught TypeError: Cannot read property 'loadTwitterPreviewData' of null
    at HTMLDocument.<anonymous> (post-edit-1470.js:1)
plugin.min.js?ver=49100-20200624:1 Deprecated TinyMCE API call: <target>.onMouseDown.add(..)
4wp-auth-check.min.js?ver=b46d314bafe4eb4f7615712825fd1647:2 Uncaught TypeError: Cannot read property 'hasClass' of undefined
    at HTMLDocument.<anonymous> (wp-auth-check.min.js?ver=b46d314bafe4eb4f7615712825fd1647:2)
    at HTMLDocument.dispatch (jquery.js?ver=1.12.4-wp:3)
    at HTMLDocument.r.handle (jquery.js?ver=1.12.4-wp:3)
    at Object.trigger (jquery.js?ver=1.12.4-wp:3)
    at HTMLDocument.<anonymous> (jquery.js?ver=1.12.4-wp:3)
    at Function.each (jquery.js?ver=1.12.4-wp:2)
    at n.fn.init.each (jquery.js?ver=1.12.4-wp:2)
    at n.fn.init.trigger (jquery.js?ver=1.12.4-wp:3)
    at Object.<anonymous> (load-scripts.php?c=0&load[chunk_0]=hoverIntent,common,hoverintent-js,admin-bar,jquery-ui-position,wp-pointer,heartbeat,autosave,suggest,wp-ajax-response,jquery-col&load[chunk_1]=or,wp-lists,postbox,jquery-ui-menu,jquery-ui-autocomplete,tags-suggest,tags-box,word-count,clipboard,post,editor-expand,thickbox&load[chunk_2]=,shortcode,wp-backbone,media-models,wp-plupload&ver=b46d314bafe4eb4f7615712825fd1647:24)
    at i (jquery.js?ver=1.12.4-wp:2)

[johnbillion]

Welcome @cartseg and thanks for the report.

These issues are due to a change in WordPress 5.5 related to the jQuery library. Check the information on this support topic under the section "jQuery Migrate is disabled by default": ​https://wordpress.org/support/topic/read-this-first-wordpress-5-5-master-list/#post-13238244

It means one or more of your plugins or the active theme are using JavaScript code that is incompatible with the jQuery change in WordPress. Ideally, these plugins (or the theme) should update their code. If no update is available at this time, there is a "jQuery Migrate Helper" plugin available on the support topic, please see the instructions there. If that solves the issues you're experiencing, please report back. That would be much appreciated so that issues triggered by this change can be better tracked :)

More technical info about the jQuery change:
​https://make.wordpress.org/core/2020/06/29/updating-jquery-version-shipped-with-wordpress/