WordPress Speed Up Service | WordPress Website Maintenance Packages Non-existent changeset UUID / Theme Not Accessible anymore!, by Joe76000 Hello Folks, – My Web site: https://www.linuxrouen.fr/wp/ – WordPress web address (URL): https://www.linuxrouen.fr/wp – Web site address (URL): https://www.linuxrouen.fr/wp – I have moved to HTTPS one year ago! – Theme: Smartline Lite 1.4.4 (ThemeZee) updated few months ago – WordPress: 4.9.1–fr_FR in FRENCH updated on Nov. 11th 2017 – PHP 5.6.30, MySQL 5.5.55-0+deb7u1-log – Linux PS: This message is published on the forums of WordPress, iThemes Security and WP Super Cache as they are potentially involved into my problem resolution. No change was done on my site before here under problem occurred, expect the updates of WordPress and the already installed plug-ins (a small dozen). All are in their latest versions. Since few weeks I have a new and very annoying behavior in the Administration (Dashboard) part of my WordPress site. PROBLEM DESCRIPTION 1. When I’m trying to go to “Apparence – Personnaliser (Appearance – Customize) I’m getting at the left the usual entries, but the rest of the screen is blank and it’s flashing twice very quickly (less than 0.1 second) the following message “Non-existent changeset UUID.” and then a little still windows display something like “Your session has expired. Please reconnect you for restarting at the last visited page”. So, I enter my IDs, and then I’m going back to the above loop with the same message “Non-existent changeset UUID.”. And back again, “Please reconnect you…”. And so on, and so on… To go back to the Dashboard, because I’m still connected!, either I click on the cross of the Customize windows or the back button of my browser. 2. When I want to disconnect completely from the Dashboard, I’m now getting a new message “You are disconnecting from your Web site. Do you really want to disconnect?”. Yes of course, what an “idiot” question! 3. Few weeks ago when everything was working well, when connected to the Dashboard, opening the Welcome page or an other page-article of my site, it was displaying the top bar of the Dashboard, which is anymore the case. PROBLEM ANALYSIS 1.I have red a lot of things on several forums including this one, but nothing was really matching with my current problem. 2. So, as usual I started to investigate my dozen of plug-ins used since 2 to 3 years. And after few days of heavy testing I found that both iThemes Security 6.7.0 (iThemes Media LLC) and WP Super Cache 1.5.9 (Automattic) were some way or an other the potential culprits, perhaps with WordPress 4.9.1 (Automattic) too. 3. For the time being the workaround I have found for being able to access successfully to Dashboard -> Appearance -> Customize is: – WP Super Cache -> Easy – No caching / Advanced – “No” Enable caching – iThemes Security -> WP Modifications -> File Editor – Deactivate file editor 4. But, as I need WP Super Cache on my site, before leaving WP Dashboard, I do need to reactivate it: – WP Super Cache -> Easy – caching activated / Advanced – “Yes” Enable caching 5. But when back to WP Dashboard I need to apply again and again my workaround: – WP Super Cache -> Easy – No caching / Advance – “No” Enable caching – iThemes Security -> WP Modifications -> File Editor – Deactivate/Activate (depending of its previous state) file editor -And of course before closing the Dashboard: WP Super Cache -> Easy – caching activated / Advance – “Yes” Enable caching ANY SOLUTON(S) ? As you can read above, it’s more than annoying to loose his time with this tricky endless game! All answers and suggestions are the welcome. Thank you. Joe Non-existent changeset UUID / Theme Not Accessible anymore!