400 due to typo about power-builder

[fussraider]

Thanks, u're right.

I lost several hours and found no other solution to this problem except to change the action name in /wp-content/plugins/tm-content-builder/framework/admin/assets/js/app/tm-pagebuilder.js :

$.ajax({
	type: "POST",
	dataType: 'json',
	url: tm_pb_options.ajaxurl,
	data: {
		/* ==============================
		    HERE "tm_pb_get_backbone_template" change on "tm_pb_get_backbone_templates"
		===============================*/
		action : 'tm_pb_get_backbone_templates', 
		tm_post_type : tm_pb_options.post_type,
		tm_modules_slugs : JSON.stringify( missing_modules ),
		tm_admin_load_nonce : tm_pb_options.tm_admin_load_nonce
	},
	success: function( data ) {
		tm_is_loading_missing_modules = false;

		try {
			localStorage.setItem( tm_ls_prefix + data['slug'], data['template'] );
		} catch(e) {
			// do not use localStorage if it full or any other error occurs
		}

		$( 'body' ).append( data.template );
		if ( data.length ) {
			_.each( data, function( single_module ) {
				try {
					localStorage.setItem( tm_ls_prefix + single_module['slug'], single_module['template'] );
				} catch(e) {
					// do not use localStorage if it full or any other error occurs
				}

				$( 'body' ).append( single_module['template'] );
			} );
		}
	}
});

[dentom]

Just a note.. if you apply this fix and some modules still don't work, clear your local storage for that website. Console > Local storage > right click your website > Delete all. Worked for me.