Driver installation not working when deploying printers via GPP

This is being caused by KB3170455 - which patches this:

It prevents point and print drivers from being installed without a warning box, unless they are packaged, signed drivers. Unfortunately a lot of printer companies do not release packaged drivers.

So far I have not found any way to get the printers to automatically install. Changing point and print settings doesn't fix it. Removing the update does fix it, but leaves a security hole.

As Grant said, the issue is caused by security update KB3170455 and the exact fix is as he mentioned. However, there is a registry edit (really a hack) that may help in some situations. It involves editing the registry on the print server and incrementing the "PrinterDriverAttributes" value by one for any driver that shows as not being a packaged driver. You will still need to make sure all appropriate Group Policy settings are in place, particularly the Point and Print Restrictions and Package Point and print - Approved Servers settings.

To avoid posting a duplicate answer, please see my answer on the other question here: Registry edit for printer drivers