Body: <p>Hi I'm getting this error on every other save when in the page editor in Craft CMS:</p>
  <pre><code>HTTP 404 – Not Found – yii\web\NotFoundHttpException
  Draft not found
  </code></pre>
  <p>The only things I am certain of are:</p>
  <p>The error only occurs after every other save.</p>
  <p>The error only occurs in the page editor and not on the public facing side of the website</p>
  <p>If there are no required fields then the edits do seem to save regardless of error.</p>
  <p>I have created a new section with no fields except the title field and when I create a page and try to edit the title of the page I still get the error.</p>
  <p>It could be something to do with the auto saving functionality. If I make an edit and hit cmd S very quickly before it has chance to think about auto saving the document then the error doesn't occur at all.</p>
  <p>In the console in Firefox when I am in the page editor there is this warning:</p>
  <pre><code>This page uses the non standard property “zoom”. Consider using calc() in the relevant property values, or using “transform” along with “transform-origin: 0 0”.
  </code></pre>
  <p>That is all UNTIL I make an edit then this warning occurs:</p>
  <pre><code>Couldn’t save draft: TypeError: n.data.modifiedAttributes is undefined
      saveDraft DraftEditor.js:875
      promise callback*saveDraft/&lt; DraftEditor.js:750
      saveDraft DraftEditor.js:699
      checkForm DraftEditor.js:675
      listenForChanges DraftEditor.js:151
      addListener garnish.js:889
      jQuery 3
  DraftEditor.js:677
  </code></pre>
  <p>I have tried cleaning out my logs folder and replicating the error and when I view the web log generated there is about 65,000 lines of code / settings of which none make any sense to me. I do not know what else to try. Any suggestions?</p>
  <pre><code>Application Info:
  PHP version     7.4.24
  OS version  Linux 3.10.0-862.11.6.el7.x86_64
  Database driver &amp; version   MySQL 5.5.5
  Image driver &amp; version  GD 7.4.24
  Craft edition &amp; version     Craft Pro 3.7.17
  Yii version     2.0.43
  Twig version    v2.14.7
  Guzzle version  7.4.0
  Plugins
  Calendar    3.3.5
  CKEditor    1.1.2
  Control Panel CSS   2.4.0
  Control Panel Nav   3.0.17
  Craft Commerce  3.4.6
  Expressive  1.01
  FacebookConnector   1.4.0
  oEmbed  1.3.12
  PayPal Checkout for Craft Commerce  1.2.2.2
  Redactor    2.8.8
  Sprout Email    4.4.10
  Super Table     2.6.8
  </code></pre>
  <p>Thanks.</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-10-20T17:48:12.963Z
Comments.Text: Can you share the version of Craft you're running?
Comments.UserDisplayName: CraftQuest
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2021-10-20T18:44:25.467Z
Comments.Text: Thanks for replying I've updated my post but it's essentially Craft Pro 3.7.17
Comments.UserDisplayName: cannon303
Tags: <craft3><404>
Title: HTTP 400 – Bad Request – yii\web\BadRequestHttpException
ThreadText: # HTTP 400 – Bad Request – yii\web\BadRequestHttpException
  
  (Asked by: username_0 on 2021-10-20)
  
  Hi I'm getting this error on every other save when in the page editor in Craft CMS:
  
  ```
  HTTP 404 – Not Found – yii\web\NotFoundHttpException
  Draft not found
  
  ```
  
  The only things I am certain of are:
  
  The error only occurs after every other save.
  
  The error only occurs in the page editor and not on the public facing side of the website
  
  If there are no required fields then the edits do seem to save regardless of error.
  
  I have created a new section with no fields except the title field and when I create a page and try to edit the title of the page I still get the error.
  
  It could be something to do with the auto saving functionality. If I make an edit and hit cmd S very quickly before it has chance to think about auto saving the document then the error doesn't occur at all.
  
  In the console in Firefox when I am in the page editor there is this warning:
  
  ```
  This page uses the non standard property “zoom”. Consider using calc() in the relevant property values, or using “transform” along with “transform-origin: 0 0”.
  
  ```
  
  That is all UNTIL I make an edit then this warning occurs:
  
  ```
  Couldn’t save draft: TypeError: n.data.modifiedAttributes is undefined
      saveDraft DraftEditor.js:875
      promise callback*saveDraft/< DraftEditor.js:750
      saveDraft DraftEditor.js:699
      checkForm DraftEditor.js:675
      listenForChanges DraftEditor.js:151
      addListener garnish.js:889
      jQuery 3
  DraftEditor.js:677
  
  ```
  
  I have tried cleaning out my logs folder and replicating the error and when I view the web log generated there is about 65,000 lines of code / settings of which none make any sense to me. I do not know what else to try. Any suggestions?
  
  ```
  Application Info:
  PHP version     7.4.24
  OS version  Linux 3.10.0-862.11.6.el7.x86_64
  Database driver & version   MySQL 5.5.5
  Image driver & version  GD 7.4.24
  Craft edition & version     Craft Pro 3.7.17
  Yii version     2.0.43
  Twig version    v2.14.7
  Guzzle version  7.4.0
  Plugins
  Calendar    3.3.5
  CKEditor    1.1.2
  Control Panel CSS   2.4.0
  Control Panel Nav   3.0.17
  Craft Commerce  3.4.6
  Expressive  1.01
  FacebookConnector   1.4.0
  oEmbed  1.3.12
  PayPal Checkout for Craft Commerce  1.2.2.2
  Redactor    2.8.8
  Sprout Email    4.4.10
  Super Table     2.6.8
  
  ```
  
  Thanks.
  
  **Tags:** craft3, 404
  
  > **Comments:**
  > **username_1**: Can you share the version of Craft you're running?  
  > **username_0**: Thanks for replying I've updated my post but it's essentially Craft Pro 3.7.17  
  
  ---
  
  ## 0 answers
  
  