Clearing Your Browser Cache
A common solution to solving an issue
AEM uses the browser to render the drag and drop editing environment. AEM tells a browser to store a number of items (code, content, graphics, etc) on your local computer to speed up the interface. This is called the "local cache". When visiting a web page your browser checks for a copy of the files in its cache. If it finds the files already cached, the page will load faster. Some browsers refer to its cache as Temporary Internet Files
When we change server settings, like permissions, a browser cache of local code can be obsolete and cause a number of issues. A common way to fix issues that only you see locally is to reset your cache.
How to Reset your Cache
Every browser has different ways to clear out the old items and refresh them with the updated one. A good source for directions is http://www.refreshyourcache.com/.