Today I updated to the OH4 Milestone.
Regarding the Jython rules I had only a small issue in a file from the helper library: “AbstractWatchService” could not be imported in 100_DirectoryTrigger.py
try:
from org.openhab.core.service import AbstractWatchService
except:
from org.eclipse.smarthome.core.service import AbstractWatchService
I tried to locate the AbstractWatchService in the openHAB sources, but it seems as if it as been removed, at least I could not find it.
I will do some more testing in the next days.