@steeeb I've tried that. I've actually tried all 4 possible drivers and none of them seem to work for any of the three generic controllers. For each driver, I do the same thing:

First, install the driver. I choose the "Pair" option for the respective driver. The dialog pops up to connect the controller through USB. I connect the controller for around 10s, and then disconnect it. I then press the PS button on the controller and.... The lights just flash repeatedly and none of them become solid, meaning that the controller wasn't able to connect.

I've probably tried the Shanwan driver the most but it's always the same result.

The error above happens I believe when the ps3controller driver is installed as the standard bluetooth daemon is disabled. The isue may be an update to the ps3controller driver which was in place for a day which had a bug. Try updating retropie-setup and removing/re-installing the ps3controller driver and repairing.