Admin Pages Not Found (plugins.php, themes.php, widgets.php, etc)

I updated my site to the version before the most recent release version of WordPress. After which, widgets.php gives me a Page not Found error. When

Thinking that an update to most recent version would fix the problem, I made another update. However, these pages now also give a Page Not Found error: plugins.php, themes.php, widgets.php, update-core.php.

I can still access my Dashboard though.

I tried searching for a fix but not one seems to be the appropriate fix. Suggestion was to disable the plugins but right now plugins.php cannot be accessed.

Any suggestions?