Support

Can you please clarify? Do you get the 404 when you see the wp-admin/admin.php?page=akeebabackupwp/akeebabackupwp.php&view=configuration page, or first you see a 404, then you are redirected to it?

If it's the former (which is most likely), I have a feeling that the problem is that your server has a server protection rule, or you are running a security plugin, which does not like the use of a forward slash in the URL. However, this is the standard way of addressing plugins in WordPress' administrator, so this rule needs to be removed.

Can you please install https://www.akeeba.com/download/backupwp-dev/9-0-0-dev202502050936-revf89a0cd7.html and let me know if that works for you?

I have two suspicions. The first one is that the forward slash in the URL may be causing this issue. The dev release addresses that by always URL-encoding it to %2F.

If this doesn't work, the problem might be that the Configuration page POSTs a JSON document to the server. This is on purpose; there are more than 100 fields on the form, which makes many servers reject the request. However, there's a very slim chance that your server does not like seeing a POST with a big JSON document sent to the browser. If we eliminate the forward slash as the culprit, we can pursue this as the other probably root cause.

All right, I think we have the second problem. You need to contact your host. Let them know that when you POST a form whose body is a well-formed JSON document you get this error. They can look into their logs for it, and tell you what you or they have to do to prevent this problem.

I am pretty sure it's a mod_security2 rule on their server which blocks the request because of its content. This would normally cause a 403 Forbidden response, but your server must've been configured to show a custom error page which doesn't exist. In this case the 403 makes the server look for the custom error page, the file does not exist, therefore the server returns a very misleading 404 Not Found error, making you scratch your head as to what happened. The solution to the problem is, of course, to disable or otherwise change the rule which was blocking the request in the first place.

You're welcome! Have a fantastic day!