OS X El Capitan downloaded but is not installing – how to fix it?

When upgrading one of our MacBook Pros today we found that El Capitan downloaded but did nothing else, still showing “download” in the App Store: El Capitan downloaded but not installing? Read this post to find out how to install it. Clicking on the “Download button here does nothing. Selecting theĀ  “Updates” tab shows this: El Capitan downloaded but not installing? Read this post to find out how to install it.Not super handy. However, assuming that it downloaded correctly we can kick off the installer from the Applications folder:   El Capitan downloaded but not installing? Read this post to find out how to install it. This one’s easy – open it as though you would any application and you should see: El Capitan downloaded but not installing? Read this post to find out how to install it. Sorted. Good luck installing the new OS and enjoy! We’re pleased so far.