We find ourselves in a chicken/egg situation with bugs in PHP's Phar class and our distribution archives.
To enable our addons to install via the '+' icon we had to change our archives to not contain any './' prefix to filenames (bug in PHP Phar). But making this change then breaks the Archive_Tar class we use internally in order to apply our upgrades and to do efficient DB backups (Phar is a pig and useless for large archives).
We would like all our customers to install the most current version of EZ Addon Tools from: https://ez-ms.com/private/ez_common4.tgz. This will allow new versions of our addons to auto-install correctly. It contains changes to the Archive_Tar class that will allow for the now missing './' prefix.
You can tell if you are having problems by examining your error_log file and if it contains a message similar to:
[30-Mar-2016 23:37:10 America/Los_Angeles] PHP Warning: file_exists() expects parameter 1 to be a valid path, string given in /home/ezms/public_html/app/addons/ez_common/lib/tar.php on line 1622
then this fix will resolve the problem.
As you know, we try to automate things so that you do not have to do anything to stay current and to get rapid deployment of defect corrections and new features. But we are unable to automate a solution to this problem.
Any questions/issues, please don't hesitate to contact us via support AT ez-ms.com.