Answers.Body: <p>I puzzled over this problem after a 4.7.28 upgrade for hours before reading this post. Turning off and on Ckeditor worked for me, which gave me another idea.</p>
  
  <p>Since this happened to me with two sites, I tried clearing all caches on the second site and that did the trick. I suspect changing the ckeditor setting flushes a cache, and flushing the cache is the real fix.</p>
  
  <p>I flushed all the caches I have so I'm not sure which is the one that really does the trick:</p>
  
  <ul>
  <li><code>drush cc all</code> (only works on drupal)</li>
  <li>Rebuild the menus: <a href="http://yourdevsite.org/civicrm/menu/rebuild?reset=1" rel="nofollow noreferrer">http://yourdevsite.org/civicrm/menu/rebuild?reset=1</a> </li>
  <li>I deleted all the files in files/css/<em>, files/js/</em>, and /files/civicrm/templates_c/en_US/*</li>
  </ul>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-02-05T19:18:08.017Z
Answers.Text: On Drupal 8, it was the menu rebuild (which also clear some Civi-specific caches) that worked for me.
Answers.UserDisplayName: Jon G - Megaphone Tech
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-02-09T19:02:54.347Z
Answers.Text: It's clearing the caches that does the job. (Wordpress, CiviCRM 4.7.29)
Answers.UserDisplayName: fred2
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-01-03T19:30:47.790Z
Answers.LastActivityDate: 2018-01-03T19:30:47.790Z
Answers.UserDisplayName: Jamie
Answers.Body: <p>I managed to trigger this error after upgrading to 5.0 (probably a directory permissions error).  Deleting the cache files as Jamie describes above AND doing the menu rebuild seems to have repaired the problem.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-04-13T14:27:05.043Z
Answers.LastActivityDate: 2018-04-13T14:27:05.043Z
Answers.UserDisplayName: breckenr
Answers.Body: <p>If I remember correctly, I had this happen one time and it was faulty html in what I was pasting in. I figured it out by pasting only a little piece of the code in at a time to find the part where I got the error.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-12-31T22:24:18.050Z
Answers.Text: Thanks for the suggestion! I went through and tested the HTML, as you suggested, and everything was fine. (But a good exercise regardless.) Turned out to be solved by disabling and reenabling CKEditor.
Answers.UserDisplayName: Erica W
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-01-01T01:23:19.690Z
Answers.Text: Good, glad to hear that disabling/enabling that worked. Odd! I'll have to remember that for next time. Thus far it's always been because of some rouge bit of code (usually because of pasted in Word stuff). :)
Answers.UserDisplayName: Jenni Simonis
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-12-21T21:01:11.097Z
Answers.LastActivityDate: 2017-12-21T21:01:11.097Z
Answers.UserDisplayName: Jenni Simonis
Answers.Body: <p>I had the same error appear after upgrading from 4.7.24 to 4.7.29 (wordpress). I was able to regain mail functionality by following the instructions above to disable the CKEditor - however, as stated above you lose the WYSIWYG functionality...</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-12-31T22:23:44.650Z
Answers.Text: Thanks, I was able to solve the problem just by disabling CKEditor and then reenabling CKEditor again the next day. Go figure!
Answers.UserDisplayName: Erica W
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-12-30T19:29:57.483Z
Answers.LastActivityDate: 2017-12-30T19:29:57.483Z
Answers.UserDisplayName: Jason
Answers.Body: <p>I ran into this because the database had not yet been converted to <a href="https://palantetech.coop/blog/converting-your-civicrm-database-use-emoji-emails" rel="nofollow noreferrer">utf8mb4</a> (it was an old installation of CiviCRM).</p>
  <p>Example: go to the Support &gt; Developer &gt; Api3 Explorer, then run entity = &quot;System&quot;, and action = &quot;utf8conversion&quot;.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-05-04T14:34:33.487Z
Answers.LastActivityDate: 2022-05-04T14:34:33.487Z
Answers.UserDisplayName: bgm
Body: <p>After upgrading to CiviCRM 4.7.28 in WordPress, when users are trying to draft mailings in CiviMail using a template (which contains unsubscribe/opt out/resubscribe/subscribe tokens, the {domain.address} token, and URLs to our website and Facebook), when CiviMail tries to autosave the draft, the user gets this error message:
  <P>"Mailing has not been saved, Content maybe out of date, please refresh the page and try again"
  <p>This error does NOT occur when not using a template, but if you use a template when you start a message, and then delete it, the error does continue to occur. It seems like it's related to the template but I can't really understand why.
  <p>Anyone have any ideas on why this would be occurring and how to fix it?</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-12-21T20:11:59.570Z
Comments.Text: Update: The error actually does happen if you don't use the template but you paste in content created by our template...
Comments.UserDisplayName: Erica W
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-12-21T20:43:51.233Z
Comments.Text: If I disable the CKEditor and use Textarea instead, in Adminster > Customize Data and Screens > Display Preferences > WYSIWYG Editor, then the error goes away, but of course that deletes the WYSIWYG functionality.
Comments.UserDisplayName: Erica W
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-12-23T00:28:53.307Z
Comments.Text: I've been seeing this reported by multiple staff members at a client that recently was updated to 4.7.28 (Drupal 7)
Comments.UserDisplayName: ericG
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-12-31T22:22:41.557Z
Comments.Text: The error was resolved by disabling CKEditor in favor of Textarea. The next day I switched back to CKEditor and the error did not reoccur with or without templates! A strange little problem but hopefully solved now.
Comments.UserDisplayName: Erica W
Tags: <civimail><message-templates>
Title: Error message in CiviMail: "Mailing has not been saved, Content maybe out of date, please refresh the page and try again"
ThreadText: # Error message in CiviMail: "Mailing has not been saved, Content maybe out of date, please refresh the page and try again"
  
  (Asked by: username_0 on 2017-12-21)
  
  After upgrading to CiviCRM 4.7.28 in WordPress, when users are trying to draft mailings in CiviMail using a template (which contains unsubscribe/opt out/resubscribe/subscribe tokens, the {domain.address} token, and URLs to our website and Facebook), when CiviMail tries to autosave the draft, the user gets this error message:
  
  "Mailing has not been saved, Content maybe out of date, please refresh the page and try again"
  
  This error does NOT occur when not using a template, but if you use a template when you start a message, and then delete it, the error does continue to occur. It seems like it's related to the template but I can't really understand why.
  
  Anyone have any ideas on why this would be occurring and how to fix it?
  
  **Tags:** civimail, message-templates
  
  > **Comments:**
  > **username_0**: Update: The error actually does happen if you don't use the template but you paste in content created by our template...  
  > **username_0**: If I disable the CKEditor and use Textarea instead, in Adminster > Customize Data and Screens > Display Preferences > WYSIWYG Editor, then the error goes away, but of course that deletes the WYSIWYG functionality.  
  > **username_1**: I've been seeing this reported by multiple staff members at a client that recently was updated to 4.7.28 (Drupal 7)  
  > **username_0**: The error was resolved by disabling CKEditor in favor of Textarea. The next day I switched back to CKEditor and the error did not reoccur with or without templates! A strange little problem but hopefully solved now.  
  
  ---
  
  ## 5 answers
  
  ### Answer by username_2 on 2018-01-03. Score: 3
  
  I puzzled over this problem after a 4.7.28 upgrade for hours before reading this post. Turning off and on Ckeditor worked for me, which gave me another idea.
  
  Since this happened to me with two sites, I tried clearing all caches on the second site and that did the trick. I suspect changing the ckeditor setting flushes a cache, and flushing the cache is the real fix.
  
  I flushed all the caches I have so I'm not sure which is the one that really does the trick:
  
  * `drush cc all` (only works on drupal)
  * Rebuild the menus: <http://yourdevsite.org/civicrm/menu/rebuild?reset=1>
  * I deleted all the files in files/css/*, files/js/*, and /files/civicrm/templates\_c/en\_US/\*
  
  > **Comments:**
  > **username_3**: On Drupal 8, it was the menu rebuild (which also clear some Civi-specific caches) that worked for me.  
  > **username_4**: It's clearing the caches that does the job. (Wordpress, CiviCRM 4.7.29)  
  
  ---
  
  ### Answer by username_5 on 2018-04-13. Score: 1
  
  I managed to trigger this error after upgrading to 5.0 (probably a directory permissions error). Deleting the cache files as username_2 describes above AND doing the menu rebuild seems to have repaired the problem.
  
  
  ---
  
  ### Answer by username_6 on 2017-12-21. Score: 1
  
  If I remember correctly, I had this happen one time and it was faulty html in what I was pasting in. I figured it out by pasting only a little piece of the code in at a time to find the part where I got the error.
  
  > **Comments:**
  > **username_0**: Thanks for the suggestion! I went through and tested the HTML, as you suggested, and everything was fine. (But a good exercise regardless.) Turned out to be solved by disabling and reenabling CKEditor.  
  > **username_6**: Good, glad to hear that disabling/enabling that worked. Odd! I'll have to remember that for next time. Thus far it's always been because of some rouge bit of code (usually because of pasted in Word stuff). :)  
  
  ---
  
  ### Answer by username_7 on 2017-12-30. Score: 1
  
  I had the same error appear after upgrading from 4.7.24 to 4.7.29 (wordpress). I was able to regain mail functionality by following the instructions above to disable the CKEditor - however, as stated above you lose the WYSIWYG functionality...
  
  > **Comments:**
  > **username_0**: Thanks, I was able to solve the problem just by disabling CKEditor and then reenabling CKEditor again the next day. Go figure!  
  
  ---
  
  ### Answer by username_8 on 2022-05-04. Score: 1
  
  I ran into this because the database had not yet been converted to [utf8mb4](https://palantetech.coop/blog/converting-your-civicrm-database-use-emoji-emails) (it was an old installation of CiviCRM).
  
  Example: go to the Support > Developer > Api3 Explorer, then run entity = "System", and action = "utf8conversion".
  
  
  ---
  
  