404 errors on posts when plugin is enabled

Here is what else I did.

I tried disabling all other plugins so that the only plugin active was the Yoast Worpdress SEO plugin. The problem remained.

I tried reinstalling the plugin and the problem still remains.

Every time I start getting 404 errors, the problem is immediately corrected as soon as I disable the WordPress SEO plugin.

Then I can re-enable it and it will work fine for some undetermined amount of time. Sometimes it is just a few hours. Sometimes it will work for more than a day. Then the problem starts happening again.

Everything was fine prior to installing the latest update – Version 1.3.4.4

For now I am forced to disable the plugin because I don’t want Google to remove my pages from the SERPs for having too many 404 errors.

Looks like this person is having the same problem as I am

https://www.ads-software.com/support/topic/keeps-crashing-1?

I thought I had version 1.3.4.3 installed, but I guess it was 1.3.4.4

So, just to be clear..

I am not sure if the problem actually started with 1.3.4.3 or 1.3.4.4

Found the problem:

I assumed that it was the Yoast WordPress SEO plugin causing my problem because if you disabled the plugin, my issue would go away.

As it turns out, it wasn’t the plugin’s fault at all. My site had been hacked. My .htaccess file had been altered and there were several malicious backdoor PHP files in the root folder for my website.
What was happening was that when I disabled and re-enabled the Yoast WordPress SEO plugin, the plugin was disrupting the redirect process that the hacker had setup on my site. That was why the problem disappeared when the plugin was disabled. After an undetermined period of time, the hacker would revisit my site and do his damage again. That is when my inner pages started getting the 404 errors.

The reason I was able to detect the hack was because I had disabled the Yoast plugin and left it disabled for more than one day. When I did that, the hacker then was able to take full control of the redirects and start sending my inner page traffic to his Russian spam/malware links. Once I saw my pages redirecting to spam – that is when the light bulb in my head lit up and told me it was a hack and not this plugin at all.

The way that the hacker got into my site was by exploiting a vulnerability in the TimThumb file that was being used by a different plugin on my site. I have since corrected the vulnerability and also removed the infection. Since then the Yoast WordPress SEO plugin has been operating as well as it always had prior to this incident.

My apologies go out to anyone who expended brain resources trying to figure out what was wrong with this plugin on my site. It was not the plugins fault at all. I am making a mental note for future reference to also check for malware/hacks the next time I suspect that a plugin is malfunctioning.

You would think that checking for malware or hacks would be common sense. Yet, my natural troubleshooting tendencies initially had me convinced it was this plugins fault. Ahhh…computers…

I hope my post helps someone else solve their issue. Beware of the .htaccess hack.

This site helped me identify the hack – https://sitecheck.sucuri.net/scanner/

I have same problem ??
and no solution until now