A lot of people have noticed some issues with the Classic WordPress editor after upgrading WordPress to version 5. Mostly due to conflicting code on the back-end.
When I upgraded my WordPress I found a similar issue. I was unable to use my WordPress editor like before. Although there a lot of improvements with the Gutenberg block editor (the latest editor), I still prefer using the classic WordPress editor as I find it more user friendly. So I tried to find a solution. I tried a lot of steps and finally found the problem was with a setting in a plugin which I will explain below. Just make sure you take a backup of your website and database before you begin. Database backup can also be taken from cPanel and from within your WordPress (from WordPress panel click Tools – Export).
I am listing out the 6 simple steps I did to find the solution.
1. Try reverting back to a previous WordPress version. Please be careful with this step, as it may stop your website from working properly. If you have taken a backup then its okay to do this step.
2. Download a previous version of WordPress and only upload the wp-admin and wp-includes folder. Also please make sure all files of the folders are uploaded to your server properly.
3. Try disabling the Plugins one by one to see what solves the problem.
4. Delete the plugins which are not active. It is also not safe to keep inactive plugins on your website.
5. If you are using a backup restore plugin from before, try restoring it to a previous date to when it was working properly.
6. Deactivate your CDN plugin or service. If you are using a CDN service please make sure to disable and check if that fixes the issue.
For me the issue was a CDN setting which was enabled in a W3C Caching Plugin. I came to know through an article I read in a forum, that CDN settings may also affect the WordPress editor and so when I deactivated mine, it fixed my editor.
If you want to continue using the old WordPress editor, try downloading and using the plugin Classic Editor. Click here to download. Its really useful if you prefer the old way of using the editor.
If you followed the above steps and were not able to properly use the Classic editor then try installing and activating Classic Editor Addon, in addition to the Classic Editor plugin. Basically this free plugin makes sure that the new block editor cannot be activated. Click here to download. I am using this plugin too.
Finally, if you have successfully started using the Classic editor then here is another plugin that will enhance its features by giving you more editing options. You can get this by installing TinyMCE Advanced. It’s an advanced version of the TinyMCE plugin. Click here to download.
Fixing the back-end WordPress editor might be a bit difficult at first. Try going through the above steps to see if this fixes your problem. Make sure to keep trying different solutions. Also make sure to disable your CDN if you are using it, just to make sure this is not causing the problem.
Have you faced this issue before and did you manage to fix it? If so what solved the issue for you? May be your answer might help someone so do comment.