Develop Reference

Cannot read property 'querySelector' of null - WordPress / Contact Form 7

Seem to be getting an error on our contact forms on version 5.4.1 and the version before using the Contact Form 7 plugin on WordPress. The error occurs when submitting the form regardless of entering information or not. The error which appears in console is as follows:
TypeError: Cannot read property 'querySelector' of null
at c (index.js?ver=5.4.1:1)
at Array.forEach (<anonymous>)
at index.js?ver=5.4.1:1
Read a couple of articles about rolling back to version 5.3.2 which I can confirm works and the issue isn't present in this version. Does anyone have a fix for it though? Or do we need to wait for another update? It's been a couple of weeks now since this was first found I believe.
If anyone needs any other information please let me know and I'll try to supply it.
Thanks!

You can edit
define( ‘WPCF7_LOAD_JS’, true );
to
define( ‘WPCF7_LOAD_JS’, false );
on wp-contact-form-7.php file.

This is due to a incompatability between your theme or a plugin with the new version of jquery used in wordpress. There are a few things you can do.
Update your theme and plugins and hope the JavaScript is patched by the author
Try to patch the broken code your self (this requires knowledge of javascript)
Install jQueryMigrate Plugin (this is only a Band-Aid and should not be the permanent solution)

CKEditor throws error after adding Notification Plugin

I am attempting to add the notification plugin to CKEditor and I receive the following error when I go on any page implementing the CKEditor regardless if it attempts to use the Notification Plugin or not
Uncaught TypeError: CKEDITOR.tools.eventsBuffer is not a function
at Area (plugin.js?t=D2LI:448)
at Object.init (plugin.js?t=D2LI:17)
at Object.<anonymous> (ckeditor.js:221)
at n (ckeditor.js:202)
at Array.m (ckeditor.js:202)
at o (ckeditor.js:202)
at ckeditor.js:203
I am clearly including the plugin since I am getting these errors.
this is the line of code in the plugin that is causing the error.
this._uiBuffer = CKEDITOR.tools.eventsBuffer( 10, this._layout, this );
Any help is appreciated.

Please see: https://docs.ckeditor.com/#!/api/CKEDITOR.tools-method-eventsBuffer.
The error means that tools object doesn't have eventsBuffer method. There are two explanations which come to my mind:
This method is available since CKEditor 4.2.1. Please check your ckeditor/CHANGES.md file (your version is at the top) to find out which editor version you use. If your editor is anything below 4.2.1, please upgrade it to latest version. Please also note that if you want to use notifications you need to use at least CKEditor 4.5 - https://docs.ckeditor.com/#!/api/CKEDITOR.plugins.notification so upgrading to 4.2.1 won't help in this case.
This is a long shot but another possibility is that you have a third-party script which conflicts with CKEditor thus you get such result. If your editor is up to date, please try disabling other scripts, clearing browser's cache according to this link and checking the result one more time.
NOTE: To find out your version you can also click question mark icon on the toolbar (it is available if you have About plugin installed).

TypeError when adding javascript to a Freeboard widget plugin

I'm making a widget plugin to display a graph from a RRD file in Freeboard (https://github.com/Freeboard/freeboard).
However, when I add the javascript for handling RRDs in the plugin, I get an exception: "Uncaught TypeError: undefined is not a function".
If I remove the line "./plugins/thirdparty/freeboard-jsrrd/javascriptrrd-1.1.1/src/lib/javascriptrrd.wlibs.js" in the external_scripts array in the file jsrrd.plugin.js, there is no exception.
What can I do to fix this?
Source: https://bitbucket.org/niclask/freeboard-jsrrd/src
Plugin file: plugins/thirdparty/freeboard-jsrrd/jsrrd.plugin.js
Thanks!

The problem was missing javascripts in external_scripts. Once I added the javascripts the graph works.

Dynamic java script zoom error in vb.net project

I inherited a legacy VB.net project that always has the following error:
document.body.style.zoom = screen.logicalXDPI / screen.deviceXDPI;
The exact error message from VIsual Studio is as follows:
JavaScript runtime error: Unable to get property 'style' of undefined or null reference
I have searched the entire solution, but none of the relevant variables/attributes show up.
I assume this is a javascript or jquery problem, the debugger says that it is a script block [dynamic] and the Call Stack says that it is global code.
Has anyone seen this error before?
Please help. Thanks in advance.

Believe it or not, removing add-ins in the browser did the trick (thanks to a colleague). It's not in the code-base at all in this case. The specific culprit was a MacAfee add-in. I never would have guessed this.

Navigation using SCORM 2004: doSetValue("adl.nav.request","continue") doesn't work

I'm using the standard SCORM 2004 4th format.
I'm using the ADL starter_template, and I tried to use the JS commands doSetValue("adl.nav.request","continue"); doTerminate(); called by a simple button, to pass to the SCO-3 from the SCO-2.
I used the starter_template manifest.
In run-time with moodle 2.6 I found this JS error:
Uncaught TypeError: Cannot read property 'children' of undefined
scorm_next
scorm_launch_next_sco
I don't know if I must modify the manifest file, in the http://www.adlnet.gov/wp-content/uploads/2011/12/SCORM_Users_Guide_for_Programmers.pdf guide is written that it should work with original manifest.
Thanks for help.

That actually sounds like a JavaScript 'bug' error. You didn't mention which LMS or portal you were using so was this ADL wrappers or tests?
Thanks,
Mark