Really Simple SSL

Known plugin compatibility issues

In some cases, there are compatibility issues with other plugins. Most of the time this is caused by another plugin blocking the mixed content fixer. The following plugins appear to conflict with Really Simple SSL:

Amazon Associates Link Builder blocks saving of settings.

Plugin Organizer Updating to the latest version of Plugin Organizer should fix the issue that other plugins are disabled after switching to SSL, but before migrating, set the switch in the Plugin Organizer setting „On“ where it says „Ignore URL Protocol“

WP Social SEO Booster: hasn’t been updated in three years, so wouldn’t recommend using it anyway

USM Premium: USM support appears to have a fix for this, or they may fix it in the next update

Genesis Toolbar Extras, thanks to Jon Burr for reporting it

SEO WordPress (not to be confused with Yoast, which has no issues with RSSSL)  output buffer issue, should be resolved in SEO wordpress. The author does not respond.

SEO Pressor SEO Pressor flushes all output buffers, including the Really Simple SSL buffer. They should only flush their own buffer.

GD Booster, thanks to Shane Blevins for reporting it

Vbout WordPress Plugin return JSON when activating the Really Simple SSL Pro license key (

Cherry Framework 3.1.5 theme prevents the Really Simple SSL pro license key from being saved. Temporarily switching to a default WordPress theme allows the license to be activated.

Deactivating these plugins should resolve your issues with Really Simple SSL.

If you encounter any plugin compatibility issues, please share this in the comments. In most cases, the problem is that the output buffer is used in a way that is not compatible with Really Simple SSL. For example, in the case of USM, the output buffer wasn’t started properly in some cases, which caused the flushing of the output buffer to flush the Really Simple SSL output buffer.





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32 Responses

  1. GD Booster
    I was having mixed content warning issues. I disabled GD Booster and they went away. GD Booster seems to be a pretty good plugin with alot of options. There is a possibility that changing an option in its settings could correct it (instead of disabling), however I’m not sure what that would be.

    1. Hi Shane, Thanks for the input. I don’t know the plugin myself, and as it’s a premium plugin can’t test it, but if you find out a setting that resolves it, please let us know!

  2. Hi Rogier,

    I love your plugin and just used it. Everthing works great EXCEPT for the fact that my homepage does not redirect to SSL. stays that way when navigated to directly. When I visit my homepage using internal links on my site it all works fine.

    My homepage is hosted by Leadpages using the Leadpages plugin for wordpress. When I deactivate the plugin, everything works great. When I activate the plugin and go to it doesn’t load the SSL version of the homepage. I need to use this plugin since I use LeadPages to design my homepage.

    Do you know how to work around this issue?

    Do you know how I address this issue?

    1. Possibly this plugin does some caching, preventing PHP execution, which prevents the php redirect from running. This can easily be solved by enabling the .htaccess redirect in settings/ssl.

  3. Hi Rogier,

    Nice plugin! I noticed that the “Under Construction” plugin (by Web factory Ltd) also causes the website to load without ssl. After disabling “Under construction”, ssl works fine again.

    1. Hi Amanda,

      what kind of errors did you experience with Jetpack enabled? There are some issues with Really Simple SSL and Photon in Jetpack, it might be enough to disable Photon.


  4. Hi, I have errors:
    “In Plugin file
    Url cannot load over https
    Found in file: wp-content/plugins/wordpress-seo-premium/premium/classes/class-premium-beacon-setting.php”
    and “CSS and JS files from other domains with mixed content”
    Probably this is conflict between your plugin and wp-rocket plugin because when I deactivate wp-rocket plugin, everything is working fine. Please help. Thanks

    1. I know there are (at least) hundreds of sites with both WP Rocket and Really Simple SSL, all working fine, so I don’t think there is a compatibility issue. The URL you have here in the results is not a valid URL: it’s only http://, so I think you can ignore this one as being a false positive. Probably there is somewhere an incomplete url on your site, causing the scan to come up with this result. The plugin will find such an URL almost anywhere in your files, so this is not a valid response. If you have any questions, let me know!

  5. So my goodness I want to use your plugin but I also use SEOPressor is okay I disable it to check the issues then reenable it after I have fixed everything?

    1. Hi Jumapili,

      since there is a known plugin conflict with SEOPressor it’s likely using Really Simple SSL and SEOPressor at the same time will result in an error. You could always try to enable and disable the plugin. Do note that deactivating Really Simple SSL will revert your site back to http://.


      1. I have reported the problem to SEOPressor hopefully they will respond with a fix. I was having problems with Slickr Flickr and something he hard coded as http but he fixed it immediatly and all reports came back just fine.

  6. That wasn’t want I mean… I am not going to disable Really Simple SSL ever. I am going to disable SEOPressor to run scans. Can you more clearly tell me what the effect would be of leaving SEOPressor running. What exactly does the Mixed content fixer do on continuing basis or is most important when the site is being scanned. Unfortunatly if it is not going to cause it to not function in some fundamental way I am going to have to ask for a refund which is very depressing. But I am fully committed to SEOPressor and have been for years.

    1. Hi Jumapili,

      it seems like the Seopressor plugin flushes the output buffer if there is any ob_list_handler. However, Really Simple SSL also uses an output buffer to put the mixed content fixer marker in the page source. The ob_end_flush by Seopressor overrides the output buffer by Really Simple SSL, thus conflicting with the mixed content fixer. This can be fixed by Seopresser by only flushing their own output buffer. The code responsible for this is in the seo-pressor.php file, on lines 483-488.

      function after_header()
      $handlers = ob_list_handlers();
      if( count($handlers) > 0 )

      The customer that reported this issue also contacted SEO Pressor about this, but we haven’t heard from them. Since it’s a premium plugin which we don’t have a license for we can’t check whether it has been fixed or not. The code is from September 2017.


      1. I have submitted your explaintion to them. Hopefully we will be able to get this resolved and I won’t have to ask for a refund from you guys… I really want to use your plugin.

      2. I am sorry you still have not answered my question. Does it matter if this mixed content fixer is not working on a persistant basis or only during a scan?

      3. Also I want you take into consideration something. You ask someone to pay almost $200 a year for the pro version of the plugin. I bet I am not your only developer account who is attempting to use seoPressor. It is a pretty common well used in the community plugin. And it seems like the list of plugins conficts is not extensive. That being said after an issues has been reported to you. Why are you unwilling as a developer to 1. Ask a plugin developer such as SEOPressor to give you a licence to test and configure against. 2. Are unwilling to pay for one license of the plugin to ensure you can test and coonfigure against it. So that you might expand your customer base? This EXCUSE that is a premium plugin is a week excuse that should never be presented to a customer even if it is true. I can assure you a customer neither cares now accepts this reasoning. I give you this bit of advice having owned a software development company that created image uploader and the way images were uploaded to facebook for a decade. Now I am willing to assist in facilitating the possible corrdination of this issue being resolved. But I would like to know you are as committed to it as I am.

        1. Hi Jumapili,

          I agree with you, that not having a license is not a valid excuse and I should have worded that differently.

          However, we take plugins conflicts seriously and do extensive testing even at the slightest possibility of a plugin conflict. We have extensively tested the conflict with SEOPressor on one of our customers sites which does have a valid license and we did manage to locate the issue. The problem doesn’t lie with Really Simple SSL but in the way SEOPressor flushes the output buffer. The problem has been reported to SEOPressor more then once but we haven’t heard anything back.


          1. Thank you for your reply. I am also experiencing the same issue and am not getting a response which is getting under my skin as I have been a longtime supporter of that plugin. And if you think I was hard on you believe me the stomping and pouting is about to get out of hand on seoPressor for not responding to 3 support emails.

            I am still wondering what the persistant issue is? Meaning and please this is my limited understanding here… If I left them both running but disabled seopressor to do a scan.

            You might have noticed I have activated several sites already and I have done it this way as I am porting 25+sites from non ssl to ssl

            Install the plugin
            Disabled seopressor
            Configured your plugin and ran scans and corrected any issues.
            Then reactived SEOPressor.

            It doesn’t appear my lock break on the the sites. (to be honest this is the most important thing to me)

            I just see the the error mixed content fixer is activated, but was not detected on the frontpage. Please follow these steps to check if the mixed content fixer is working

            If I notice a broken lock later on a site and disable seopressor and run scans to fix it. Can’t this be a kind of work around or am going to wake up tomorrow and find because of that error all my locks are broken for no apparent reason? And then I have to lose my mind?

          2. Hi Jumapili,

            I’ve checked a couple of your websites on which the plugin is activated and indeed, the mixed content fixer is not detected on the frontpage. Really Simple SSL checks if the mixed content fixer is working by inserting a marker in the page source, ‘data-rsssl=1’. If this marker is found in the html, it’s active. Because of the conflict with SEOPressor the mixed content fixer is blocked from working and the marker is not being inserted. However, the fact the plugin cannot detect the mixed content fixer doesn’t mean that there will be mixed content on your site. On the sites I checked you have the green lock, so even though the mixed content fixer is not active, there’s no mixed content. Mixed content doesn’t appear out of nowhere, so you don’t have to worry about your sites suddenly breaking.

            However, when you do encounter a site with mixed content the mixed content fixer won’t be able to fix this. When this happens this can be fixed by disabling SEOPressor or by manually fixing the mixed content and leave SEOPressor enabled. For assistance with that you can always send us a message.


  7. Mark,

    I gave you all kinds of the business over this so I wanted to give you an update. After sending seo Pressure 5 Emails. I finally got a response that was a canned response. Something like we will forward this to the engineers. When I asked when will I get an answer and 5 more emails its all crickets over there… SO that being said guess what plugin I am going to drop it is not going to be yours I can assure you. Damn but yoast is a bit expensive with so many sites. Any other suggestions I won’t hold you responsible just don’t even know what to pick at this point and I have so many sites.

  8. I personally prefer Yoast, but there are some other SEO tools as well that should do very nicely. Personally, I think good support is the most important thing, and in my experience Yoast has great support.

  9. I have a problem with the supreme shortcodes plugin, when I activate it my site remains blank and only the administration panel works. I think it’s to blame supreme shortcodes

    1. Hi Christian,

      indeed sounds like an issue with the supreme shortcodes plugin. I’d suggest to contact their support about this issue.


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