may be this HowTo will help solve your problem
Error 412 Precondition Failed (Error 412 Precondition Failed) is a notification from the HTTP side that indicates that access to a resource was denied. A resource can be not only the site as a whole, but also individual elements: images, audio and video content, individual scripts or plugins.
It should be noted that the 412 Precondition Failed error occurs in two cases: in the client’s browser and on the site administrator’s side. In the first case, if you are sure that the site should open, you should clear the cookies in your browser. In the second, most likely you made changes to the site. Often, error 412 occurs for administrators whose server uses Windows.
For the site administrator: causes of error 412
- Error 412 occurs after changes on the site, often global changes. For example, you decided to change the site code to set watermarks on all images in the site’s posts. When editing a post, error 412 may occur. This case is associated with Windows Live Writer. The system generates error 412 Precondition Failed - precondition not met.
- When using Windows Server 2008 in the Standart SP 1 package, you may find error 412 in the log. This may be due not only to changes on the site itself, but also corny - hardware change. Upgrading to SP 2 probably won’t solve anything. Read what to do and how to fix error 412 for a webmaster in the next section.
- Changes with plugins and changes in the site theme. When you change the design of the site in a package through the admin panel, for example, in WordPress. Those. you purchased a template package and tried to install a new theme. Also with plugins. By the way, often the WP Super Cache plugin leads to error 412, and not only on the part visible to the user, but also in the administrative part. At the same time, this is the result of a conflict between the caching settings on the server itself and the settings of the installed plugin.
Causes of error 412 from the user side
From the user’s side, the error occurs only in one case - a crash in the browser. Chances are, almost all of the sites you’ve opened before will stop working. If the problem is with only one site, that’s not your problem. It’s simple.
How to fix error 412 Precondition Failed?
The least action needs to be taken by the user. That is why, let’s start the list with solutions for the average user. By the way, there is a site in the Google search results where any error, even a 404 error, is treated by cleaning the registry or reinstalling the Windows system. Guys, this is complete nonsense. In solving error 412, you should not do any manipulations with the system on the part of the user.
Fixing error 412 for a regular user
As mentioned above, if you see error 412 when entering the site, don’t panic. First of all, try the simplest thing - restart your browser. Did not help? In this case, you need to clear the cookies. Usually users don’t do this for years. You can clean all browsers at once using CCleaner - the program is free. Just download, install and in the cleaning section, follow the prompts to clean up.
How to clear cookies without programs to remove error 412 in the browser? We list several popular browsers and paths for finding a function in the program. Attention: all site data is deleted, including saved passwords (if you delete a complex of cookies, history, autocomplete, etc.).
Opera. Click on the Opera icon in the upper left corner, then look for “Settings”. Then we select the items: Security - All cookies - select all - click delete.
Google Chrome. In a new empty tab, press the key combination - Shift + Ctrl + Del. We put all the checkboxes, select the “Clear all time” time and delete.
Mozilla Firefox. In the upper right corner there are three strips (click) and look for the “Settings” item. You will see a page where in the left column you need to select “Privacy and Security” - click. Look at the “Cookies and site data” section and click on “Delete data” there. Confirm - “Delete”.
What should a site administrator do?
- In the first case, which is described above, try simply restoring the site from a backup. Usually, any self-respecting hosting company makes daily backups. This can be done if you have made many edits to the site and do not know which edit or change caused the error. Advice for the future - made edits, checked the site. Error 412 Precondition Failed will go away after restoring from backup. Just in case, you need to restore both the site and the database.
- If error 412 occurs on Windows Server 2008, you can reinstall the system. But a better solution is to install Update. If you have SP 1, updating to SP 2 will not change anything. To fix error 412, you can also simply reinstall the system from scratch. These manipulations should be done if you are 100% sure that the error is not related to the latest changes on the site that you made.
- If you find error 412 on the site, you must immediately go to the Google console. Check which pages crashed initially. Perhaps, if the error occurred a long time ago, these pages dropped out of search. It is sad. We’ll have to work. Start by rolling back your changes, for example uninstall recent plugins. In parallel, you need to test the site on different devices.
In general, a webmaster’s error 412 occurs due to inaccurate editing of the code, so always make a backup copy before any edits