I added a wp_grin plug-in to my wordpress, and to make it work, I called the smilies to my Quicktags.js file as the instructions told me to do. When reuploaded my quicktags.js, the Quicktags no longer show when I write a post.
A small mistake/omission in the code suffices and the quicktags won’t show. You probably need to check again, whether everything was pasted as it should be and whether you accidentally disrupted a function or deleted something.
My problem isn’t that the quicktags are gone. They are still there, but clicking them (as well as other plug-in related buttons) doesn’t cause the function to work. So far, I’m not able to use IImage Browser, tag, tags, and check spelling buttons on the create/edit post page.