I recently tried to update my Oracle Jdeveloper installation with some updates coming from Oracle. You can update your Jdeveloper installation by clicking "help" - "Check for Updates". I needed to install some updates including the "AIA composite application framework version 2.4" update. When selecting it a process is started and after that you are requested to restart your Jdeveloper installation. This should complete the process and you should be able to use the new version. However due to some reason the new functionality was not installed. When checking for updates again I also found the "AIA composite application framework version 2.4" update still in the list of updates to be installed.
After some time I found that if I started Jdeveloper from the command line I could see a error messages stating the following: "oracle.ideimpl.webupdate.task.TaskFailedException: Unable to read /Users/suntac/.jdeveloper/tmp/update/oracle.aia.caf.jdevextension.2.4.zip". When jdeveloper downloads updates it is storing it under a tmp/update folder as a .zip file. Upon looking into this location I found that the file was empty.
Thanks to William from the Oracle jDeveloper support team I was able to download the file myself by hand. You can check manually all the updates at the "Oracle Extensions for Oracle JDeveloper Update Center" which is located at http://www.oracle.com/ocom/groups/public/@otn/documents/webcontent/131167.xml . Now when you download the file you can again start the "check for updates" option under the help menu however no pick the option to select from a local file.
At this screen you can select the location of the zip file you just downloaded. You will again be asked to restart jdeveloper and now you will notice that the file is installed without any issue.