Well, if a broken OH has this fundamental impact, I would recommend to work with two environments. One is a production, and the other one is a test environment (can be a copy of your production), this allows you to test stuff before you put it in production.
I recognize the symptoms. Did you saw anything strange in your openhab.log? Something like this?
2017-11-25 13:48:11.172 [WARN ] [org.apache.karaf.services.eventadmin] - EventAdmin: Blacklisting ServiceReference [{org.osgi.service.event.EventHandler, org.eclipse.smarthome.core.events.EventPublisher}={event.topics=smarthome, component.name=org.eclipse.smarthome.core.internal.events.OSGiEventManager, component.id=52, service.id=149, service.bundleid=111, service.scope=bundle} | Bundle(org.eclipse.smarthome.core_0.9.0.201711242229 [111])] due to timeout!
Did you try to clear the cache?