4.1.1 -> 4.1.2 Upgrade Problem: "fatal Error: Class 'phardata' Not Found In /public_Html/store/app/functions/fn.fs.php On Line 187"

Hi, I cannot run the 4.1.1 to 4.1.2 upgrade. Clicking Install results in the following on an emty web page:

"Fatal error: Class 'PharData' not found in /public_html/store/app/functions/fn.fs.php on line 187"

Any ideas how to fix?

UPDATE: looks like this happens when PHP 'Phar' module is not active on the server. No idea how to fix this though.