I've been running Java 8 update 40 in order to maintain backward compatibility with detail markers originally placed in .pln files started in 17 or earlier.
I installed the update and I thought I was in the same boat as Mskov with the latest 5005 update. But the ArchiCAD splash screen came up after about 5 minutes. And then the clue - a Java prompt. I installed the latest Java and rebooted. Now it works as normal.
AC19-23 | Win10 Pro | i7-8700K | Quadro P600 | 500gb 960 EVO M2 | Dual 28" 4k Samsung U28E590