I see the following error when increasing / decreasing the temperatures for room thermostats…
2016-06-02 18:21:22.571 [WARN ] [t.i.s.MapTransformationService] - Could not find a mapping for ‘-’ in the file ‘en.map’.
My idea is to have clean running demo before I start using openHAB for my automation.
It’s a warning, not an error …
Edit your en.map and add a line like:
-=undefined
and the warning will dissappear (the dash means the same as undefined).
Huh, you again… hi sihui, thanks for your reply…
A little anecdote: I used to work in a large commercial enterprise, hundreds of servers… nothing got onto them unless it would not produce ‘red events’ (errors). At one point we swapped a the backup software on all servers when the vendor wasn’t coming to the party fixing it.
With this mind set in mind mind, like it was said somewhere else: like buying a new car and the “check engine” light comes on, I am wary, as – no matter whether commercial or open source – you want people to use your stuff, yet, not even the demo works flawlessly… a big negative for me.
In any case: I made the mapping in en.map and the warning is gone. 
What part doesn’t work?
A lot of people switch to openHAB because they are not satisfied with the other open source or closed source software available.
After a while you will see that openHAB is the most configurable and customizable home automation software available 
Okay, disregard, found your post about the weather binding …
The demo has at least three problems:
I understand that all hands are on deck for v2, but I think, someone who understands this thing should remove Yahoo weather and pick something else or leave it out, and fix error 3.
It simply leaves a bad taste for any newbie when like someone else nicely described: you buy a new car and the ‘check engine’ light comes on.