Post not publishing after inserting image

My posts are not being published after inserting an image. After inserting image in the post when I click publish button it directs me to the homepage. I even can’t update my posts. I have faced similar problem 2 years before aswell. I solved it by unchecking some function in cpanel. I just forget what I did then. I googled it out but can’t find solution. Please someone come with solution.