CFS Plugin conflict with WP 4.9.1?

My site seems to display just fine, but my WordPress dashboard interface had problems. I have eliminated all other plugins and the problem will repeatedly produce the same results when the Custom Field Suite plugin is enabled.

I log in to my WordPress dashboard. I choose Pages from the menu, then select a page to edit. In the page editor, I can switch back and forth between the Visual and Text tabs as normal – Unless I click the update button while on the Text tab. Clicking update with the Text tab selected produces the following error (copied from my Chrome browser console):

VM5855 post.php?post=48&action=edit:2131 Uncaught TypeError: Cannot read property 'indexOf' of undefined
    at HTMLDivElement.<anonymous> (VM5855 post.php?post=48&action=edit:2131)
    at Function.each (jquery.js:2)
    at jQuery.fn.init.each (jquery.js:2)
    at jQuery.fn.init.$.fn.init_wysiwyg (VM5855 post.php?post=48&action=edit:2102)
    at HTMLDocument.<anonymous> (VM5855 post.php?post=48&action=edit:2092)
    at i (jquery.js:2)
    at Object.fireWith [as resolveWith] (jquery.js:2)
    at Function.ready (jquery.js:2)
    at HTMLDocument.K (jquery.js:2)
(anonymous)	@	VM5855 post.php?post=48&action=edit:2131
each	@	jquery.js:2
each	@	jquery.js:2
$.fn.init_wysiwyg	@	VM5855 post.php?post=48&action=edit:2102
(anonymous)	@	VM5855 post.php?post=48&action=edit:2092
i	@	jquery.js:2
fireWith	@	jquery.js:2
ready	@	jquery.js:2
K	@	jquery.js:2

Once I’ve done this, it also causes the page editor to no longer switch back to the Visual tab from text. If I click on the Visual tab, the tab is highlighted, but nothing happens.

Subsequently, if I navigate away from this page and then return to the page editor once this has happened, loading the page editor produces the following error:

post.php?post=48&action=edit:2130 Uncaught TypeError: Cannot read property 'indexOf' of undefined
    at HTMLDivElement.<anonymous> (post.php?post=48&action=edit:2130)
    at Function.each (jquery.js:2)
    at jQuery.fn.init.each (jquery.js:2)
    at jQuery.fn.init.$.fn.init_wysiwyg (post.php?post=48&action=edit:2101)
    at HTMLDocument.<anonymous> (post.php?post=48&action=edit:2091)
    at i (jquery.js:2)
    at Object.fireWith [as resolveWith] (jquery.js:2)
    at Function.ready (jquery.js:2)
    at HTMLDocument.K (jquery.js:2)
(anonymous)	@	post.php?post=48&action=edit:2130
each	@	jquery.js:2
each	@	jquery.js:2
$.fn.init_wysiwyg	@	post.php?post=48&action=edit:2101
(anonymous)	@	post.php?post=48&action=edit:2091
i	@	jquery.js:2
fireWith	@	jquery.js:2
ready	@	jquery.js:2
K	@	jquery.js:2

There are other issues that this conflict produces as well. Once the issue begins, and for as long as the CFS plugin is enabled, I have problems using The Event Manager plugin also. When I select an event to edit, the Location and Organizers options, which normally have drop downs, no longer work, and loading that Edit Event page produces the following error:

post.php?post=3249&action=edit:2790 Uncaught TypeError: Cannot read property 'indexOf' of undefined
    at HTMLDivElement.<anonymous> (post.php?post=3249&action=edit:2790)
    at Function.each (jquery.js:2)
    at jQuery.fn.init.each (jquery.js:2)
    at jQuery.fn.init.$.fn.init_wysiwyg (post.php?post=3249&action=edit:2761)
    at HTMLDocument.<anonymous> (post.php?post=3249&action=edit:2751)
    at i (jquery.js:2)
    at Object.fireWith [as resolveWith] (jquery.js:2)
    at Function.ready (jquery.js:2)
    at HTMLDocument.K (jquery.js:2)
(anonymous)	@	post.php?post=3249&action=edit:2790
each	@	jquery.js:2
each	@	jquery.js:2
$.fn.init_wysiwyg	@	post.php?post=3249&action=edit:2761
(anonymous)	@	post.php?post=3249&action=edit:2751
i	@	jquery.js:2
fireWith	@	jquery.js:2
ready	@	jquery.js:2
K	@	jquery.js:2

All of these problems and errors disappear once the CFS plugin is deactivated.

I hope you can use the information above to provide an update that will allow your plugin to work properly with WordPress 4.9.1