WordPress 4.9 Error – Unable to Edit Files – Resolved

Recently, on November 16, 2017,  WordPress released its latest version. WordPress 4.9 “Tipton”. Named after a Jazz musician, Billy Tipton. That news may sound like a (Jazz) music to the WordPress users’ ears but not for long. The new WordPress, encountered an error. This is not something new. In fact, just like any other release, there are many errors which eventually get resolved. Hosomwever, input from the WordPress community is necessary in order to get a hold of whatever’s wrong and this article is one such attempt. 

So the story is that my web hosting provider, auto updated my blog to the latest version of WordPress 4.9. That’s convenient but for the first time ever since I started using WordPress, I encountered an error immediately after the update. The error was that I was unable to edit any of my file in the WordPress Editor.


Finally, of course, with the help of the volunteers on the WordPress’s forum I was able to resolve the WordPress 4.9 Error so I thought why not share my resolution with many of the other WordPress users out there who might be facing the same problem.


After all, it’s all about giving back to the community. Right?


However, before going further, here’s a small but necessary disclaimer.


First, I truly admire WordPress as a CMS platform and this article is in no way to degrade the platform in any sense. The errors are normal part of the development process and they are acceptable as long as they don’t damage your blog/website significantly.

Second, the solution below of course, does not apply to all the WordPress users. There may be many reasons for the same issue and it’s literally impractical to test all of the solutions. So I’d rather stick to the problem that I faced, resolved, reproduced and then resolved again in order to make sure that the problem identified was in fact a problem.


So once we’ve gotten the disclaimer covered, let’s start with the details of the error and how I resolved it.


WordPress 4.9 Error – Unable to Edit Files in WordPress Editor

As the heading suggests, soon after the update, I was unable to edit my header.php file. I wanted to apply some changes in the file and wasn’t able to do so.

As soon as I’d hit the “Update” button after making the changes, it’d keep on processing and would end up giving the following error:


“Unable to communicate back with site to check with fatal errors, so the PHP change was reverted. You will need to upload your PHP file change by some other means, such as by using SFTP”.


Wordpress 4.9 Error - Unable to Communicate-min


To be honest, this wasn’t the only that was showing up. After couple of tries more, it gave me “Scrape Nonce Check Failed” error as well. However, after a day, when I tried to reproduce this error, I couldn’t. So I’ll just keep it to this, “Unable to communicate…” error only.


Following The Obvious Path

Of course, I googled the issue and found that there are dozens of other people with the same issue as well.

So WordPress 4.9 Error that I was facing wasn’t just confined to me.

After this confirmation, I scrolled for the solution and found it to be too technical.

Don’t get me wrong. I don’t mind barging into the “Technical Realm” but I prefer applying Occam’s Razor for the resolution of my issue.

So I started searching for rather simpler solutions.

After some more research, I thought why not look for the solution purely from my perspective. Hence, I went on to create my own thread on the WordPress forum


Response On My Thread.

After few hours, I received a response from the moderator, Steve Stern who asked me to install Health Check plugin and report back its findings.

Steve Stern - Health Check Plugin-min

Just for summary, health check plugin generates a report of your WordPress, PHP and database information so in many cases, it’s quite a handy detection tool.

Following the tip, I installed the plugin and when tried to use it, again, it kept on loading and eventually the browser ended up with Error 504 – Gateway Timeout.


Another WordPress Volunteer To The Rescue

Needless to say, I updated this on the WordPress thread and then another good fella (or girl) advised me to primarily deactivate my Contact plugin and then report any update. She also suggested me that I might be having WP_CRON error as well while some other plugin could also be causing the problem.


Wordpress 4.9 Error - Yui Solution


For a moment, I thought to be trapped in the abyss of errors after errors but I had no choice. So I went to my plugins list to deactivate my contact plugin.


No Contact Plugin

As soon as I landed on my plugins list page, I remembered that couple of days back, I deactivated and deleted my previous contact form plugin. While I installed another one but I never activated it.

So the error due to contact form plugin was out of equation.

The only option left for me to apply the trial and error methodology and deactivate plugins one by one while at the same time keep checking if the error is resolving.


Sometimes, Laziness Pays Off

I started looking for the plugin to be the first member of my hit list and to be honest, I did not want to deactivate majority of them as all of the plugins were playing key role in the functioning of my blog. Additionally, I also feared that I had to reconfigure some of the plugins in case I reactivate them.

Truly speaking, I was just being lazy.


I started looking for the plugin which would have the least impact if I deactivate it and there you go, I found one.


This plugin was Shortpixel Image Optimizer.


My Lucky Day

I deactivated Shortpixel Image Optimizer, went straight to Appearance→Editor, applied some comments in my header.php file, clicked “Update File” and voila…!


It worked…!


It must be my lucky day as deactivating the very first plugin did the trick for me. As an afterthought, I should have bought a lottery ticket but alas, I exhausted my good luck on this WordPress 4.9 error.


Reproducing The Same Issue

To be sure that the the solution is indeed not a fluke, I decided to take a rather more scientific approach and thought that before announcing my “major discovery” to the world, I should be confident that error was indeed because of that plugin.

In that case, if I reactivate the plugin, I should be 100% sure that it will reproduce the same issue. In case not, then even though I might have resolved the issue for myself but that’s it. I could not suggest it to anyone else.

So this is what I did. Went to my plugins list. Reactivated the Shortpixel Image Optimization plugin, edited my header.php file and clicked the “update file” button.

The error appeared one more time.

Indeed the plugin is having issue with the WordPress 4.9 version. So I went in the “Add New” section of the plugin area in order to see if the plugin is compatible with the latest WordPress version.

To my surprise, it says it is.

Wordpress 4.9 Error - shortpixel image optimizer-Compatibility


Seems like that the developers haven’t been informed yet. So I took it on myself and have emailed them about the issue.

I’m sure they will eventually figure it out.


What’s The Crux Of The Matter

The crux of the matter is that while there may be more than one causes of the above WordPress 4.9 error, it’s good to first see if the solution that I’ve jotted above applies to you as well.

If yes, then I’d be glad of being of some help. In case not, then I’d suggest you to start your own thread on WordPress forum and see if that helps. Additionally, if you resolved the error it’d be great to share your solution either below in the comments section or in some other forum so that anybody else can gain benefit from it.


Good bye for now.


I recently checked if the WordPress issue is still there by updating the plugin Shortpixel Image Optimizer to version 4.8.7.

After updating, I can edit and save my files in the WordPress File Editor section. So the WordPress 4.9 Error due to Shortpixel Image Optimizer plugin is resolved and you may no longer need to deactivate the plugin.

Simply updating it to the latest version will do the trick now.

21 thoughts on “WordPress 4.9 Error – Unable to Edit Files – Resolved

  • November 23, 2017 at 5:23 pm

    Great great words, but I don’t have that plugin activated. There has to be a function in that plugin causing the error used by many other plugins. WordPress fucked up..

    • Saad
      November 23, 2017 at 8:32 pm

      Hi LordComander,

      Yes, there’s a function in the plugin which is/was causing the error. If you follow the link above to the WordPress forum in which I created my thread, you will see that the one of the experts have identified that particular function.

  • December 14, 2017 at 9:11 pm

    The problem is stil there :

    “Unable to communicate back with site to check for fatal errors, so the PHP change was reverted. You will need to upload your PHP file change by some other means, such as by using SFTP.”

    I don’t use any Shortpixel Image Optimizer. plus my contact form plugin is also updated

    but the problem is still there, I can’t save php files any more.

    • Saad
      December 15, 2017 at 9:51 am

      Hi Bhaiji1,

      It’s not necessary that there’s only one plugin causing this issue. What I wanted to tell from my post was the methodology that you need to follow in order to resolve your issue.

      First things first, start a new thread on WordPress
      Second, perform health check just like I did
      Third, start deactivating plugins one by one and see recheck issue after each deactivation and see which plugin is actually the “problem child”.

      I hope this will clear some confusion and help resolve your issue.

      Thank you.

  • December 15, 2017 at 1:01 am

    The link is not working, I have no plugins active and have this error for weeks now.
    There are several hundred cases out there, which make me think, if wordpress the right plattform.

    There really should be a fix for this out there for such a big problem.

    • Saad
      December 15, 2017 at 9:48 am

      Hi Rene,

      Sorry to hear about your problem. What link are you talking about which is not working?

      Worpress surely is the best platform for blogging there’s no doubt about that. All the errors are part and parcels of any cms software which keeps on updating.

      What I’d suggest to you is to perform the health check and see if it identifies anything.

      Moreover, start a thread on WordPress forum so that a proper record is maintained. The professionals over there will help you out in a much better way.

      Thank you.

  • December 29, 2017 at 9:10 am

    you know what, i deactivate all my plugins…
    yes all my plugins…
    but same issue there…arrrggghhh…

    • Saad
      December 29, 2017 at 12:02 pm

      Hi Hakim,

      Sorry to hear about what happened with you. Did you raise this issue in the WordPress forum?

  • December 30, 2017 at 6:56 am

    It’s not just about plugin.

    I have 4 sites, they are mostly identical, same plugins, same themes.

    After upgraded to 4.9, two of them started to have this uploading problem and the other two works fine.

    It’s not just about plugins. Your article wastes 5 minutes of my life.

    • Saad
      January 1, 2018 at 6:46 pm

      Thanks for reading my article and your input High5.

  • January 6, 2018 at 3:56 pm

    I uninstalled all the plugins still it dint work.i m trying to edit the header.php..can u please help me with this..
    or can you provide the name of that particular function???

    • Saad
      January 7, 2018 at 6:42 pm

      Hi Minal,

      Did you perform the health check? What error did it give?
      BTW, if you follow the conversation in the forum above you’ll see the function referred by one of the WordPress representative.
      I hope that’d help.

  • January 7, 2018 at 10:37 am

    I deactivated all the plugins even cleared the browser history and website history still the error stays the same.could you please help me with the some another solution or the name of that particular function that is creating the mess..have been dealing this issue from long but cant figure it out..

    • Saad
      January 7, 2018 at 6:39 pm

      Hi Minal,

      Did you perform health check? What error did it give?

      • January 7, 2018 at 9:25 pm

        Yes i performed health check,but that did not give me any error..

        • Saad
          January 8, 2018 at 2:26 pm

          Hmmm…! As you’ve said, you’ve disabled all the plugins as well. Right?

          Have you created new thread on WordPress forum?

  • January 14, 2018 at 3:16 am

    I had this problem on my WordPress site. It happened because my URL was at https and the cert was invalid due it being on a shared hosting platform. When I changed the logged in URL to http I no longer got the error and could once again make changes to my theme php files in the online editor.

    • Saad
      January 14, 2018 at 11:01 am

      Hi C Finkelman,

      Thanks for sharing your issue and the solution. I appreciate it.

  • January 16, 2018 at 12:43 pm

    I had the same problem when I bought a new theme. Couldn’t fix it until I decided to upgrade to the latest php version. At that time it was php 7.1

    I did the compatibility checks and was OK then I set my host to use 7.1 Viola All was then OK.

    • Saad
      January 17, 2018 at 10:56 am

      Hi Wilf,

      Glad to know you were able to resolve your issue. One suggestion that I’d like to give is that publish your resolution either on your blog or WordPress forum so that other people can also benefit.

      Thanks for taking time and commenting.


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