I can not log in the WP dashboard

I managed to solve the problem so I temporarily renamed to something like / wp-content/pluginsXX / and they will not be recognized. Then reported to the WP dashboard. After that, rename the folder back / wp-content/plugins and everything is working properly. Ten days ago, I tried to solve this problem that we appeared when installing a new version of WP wordpress-3.9.1-en and I finally succeeded. I am writing this to help people who are in our same situation.