When trying to save products or settings goes to "Page Not Found".

Hello, suddenly my store version 2.0.3.1 started with a problem that if I try to edit a product or settings in the store does not save, it just goes to "Page not found" but not saved. I have already changed all the folders by backup but the problem continues, I do not know what else I can do.

Can anyone give a hint what else can I try to fix the problem?

Have you looked in your log files in Opencart and on your server? it's an unusual problem.

Also if you've recently added new modules I would disable these one at a time and see if that fixes it.

I did not add any recent modifications, I tried to install a watermark module to test, but I uninstalled and removed all modules folders via ftp. Now, to try to solve the problem, I even deleted the public_html folder and resubmitted a backup, but it did not solve the problem, I just did not try to mess with the database to not lose the transactions of the last orders, I do not know if DB can solve the problem.

You could try upgrading or reinstalling Opencart, do you have a database backup before or after the problem?

Did you see this post?
viewtopic.php?t=17923

Hello, reinstalling the store is no solution for me because I have many modifications and store settings and I can not miss it. The backup I have is 3 months so if I back up the database I will lose many customers and orders. I think there is no solution, if I have to reinstall the store and lose everything I have then I will test another platform outside opencart. Thank you.

You can use something like firefox/firebug or Chrome, right click on the save button and choose 'imspect element' and see what the url is for the save button.

Problem solved. the error was on the server, I changed the server and everything worked again.