Just downloaded and installed PL4. PL4 hangs as screenshot shows. Yes, I rebooted:
Gregor, 2004 is an optional update - since it is known for various issues, I did not install it.
1909 should be fine according to DXOs specs: https://support.dxo.com/hc/en-us/articles/360048398011
Had not deleted old stuff from beta phase, sorry for the fuzz!