Prerequisites

• I have searched for similar issues in both open and closed tickets and cannot find a duplicate.
• The issue still exists against the latest stable version of Elementor.

Description

Normally I can resize a column by changing the "Column Width" field.

But sometimes the column width will refuse to apply/save the new value and will throw this error:

Uncaught TypeError: Cannot read property 'errors' of undefined
    at n.onEditorInlineSizeInputChange (editor.min.js?ver=2.1.6:2)
    at i.function.l.(/wp-admin/anonymous function) [as validationMethod] (https://example.com/wp-content/plugins/elementor/assets/js/editor.min.js?ver=2.1.6:2:217231)
    at isValid (editor.min.js?ver=2.1.6:2)
    at i.function.l.(/wp-admin/anonymous function) [as isValid] (https://example.com/wp-content/plugins/elementor/assets/js/editor.min.js?ver=2.1.6:2:217231)
    at editor.min.js?ver=2.1.6:2
    at Array.every (<anonymous>)
    at n.onBaseInputChange (editor.min.js?ver=2.1.6:2)
    at HTMLDivElement.dispatch (load-scripts.php?c=0&load[]=underscore,shortcode,utils,jquery-core,jquery-migrate,backbone,wp-util,wp-backbone,media-models,moxiejs,plupload,wp-plupload,jqu&load[]=ery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-sortable&ver=4.9.8:11)
    at HTMLDivElement.r.handle (load-scripts.php?c=0&load[]=underscore,shortcode,utils,jquery-core,jquery-migrate,backbone,wp-util,wp-backbone,media-models,moxiejs,plupload,wp-plupload,jqu&load[]=ery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-sortable&ver=4.9.8:11)

It only happens from time to time, so it was difficult to figure out what the trigger is.

It turns out that it's caused by moving a Section (row) that has a Column widget inside of it.

Steps to reproduce

1. Create a page that uses Elementor
2. Add a Section to the page.
3. Add another Section to the page that contains the Columns widget.
4. Move the Column widget's Section to another location (you have to move it somewhere different; it can't remain in the same spot).
5. Click Edit Column on one of the columns
6. Attempt to change its Column Width under the Layout tab.
7. The column will not change in size, nor will it save your new value. Additionally, the console will produce that error.

Here's a video summarizing those steps and demonstrating the error:
Streamable link
Zipped MP4 file

This issue has occurred on two very different environments, one of which was almost a fresh install of WordPress but had Elementor installed.

Updating and refreshing the page will fix the issue, so my guess is that some kind of column reference isn't being copied when the Section is moved. Interestingly, you can still manually drag the column divider to change their widths.

Isolating the problem

• This bug happens with only Elementor plugin active (and Elementor Pro).
• This bug happens with a default WordPress theme active.
• I can reproduce this bug consistently using the steps above.

Environment