Web interface freezes

I decided to upgrade to OH3 from OH2 with a fresh install. My plan is to build up everything from the scratch, but planning to use the old scripts.

So far I have installed the bindings and I’m setting up the items. I have several different types of equipment to control (Z-Wave, Telldus, MQTT etc.)

My problem is that the web pages freezes every now and the and it makes it hard to get the system up and running. It’s like the web core functions are running, but the content keeps loading and loading…
Finally I have to reboot the system with ssh-console.
Log files does not contain any errors (Viewing the log with frontail)
Usually this happens when trying to open “Things” section from the side bar.

Any idea how to find a solution for this?

Openhabian: 3.0.0
RPI3B rev 1.2