tmce-active class bug

In my self hosted WP site, if i login as administrator, the text in the text editor is visible but the problem arise when i login as editor or author, the text in the text editor goes white so text is not visible. Inspecting on it, seems like “.tmce-active” class is making this happen. To be precise “.js .tmce-active .wp-editor-area” css class just have “color:#fff” which is causing the problem. I have deactivated this TinyMCE and removed it from the plugin, assuming this might be causing the problem, but problem still exist.