When I click the "Update Now" button for any plugin, it redirects to a 404 page not found.
There is a problem with update URLs. For example, the "Update Now" URL for "Contact Form 7" is as bellow
All plugins are in same status. "Update now" URL is in following format "/wp-admin/VERSION-NUMBER-OF-PLUGIN", which result in 404 page.
I have disabled all plugins but it didn't help.
Any ideas what could be the issue?