OH1.8: The name 'unkown' ... cannot be resolved to an item or type

[Max_G]

And as far as the brckets in the createTimer are concerned:

How to 'createTimer' and 'Timer.cancel' when item change state?

Both are equivalent. From the Xtext docs: When a method call’s last parameter is a lambda it can be passed right after the parameter list. For instance if you want to sort some strings by their length, you could write : Collections.sort(someStrings) [ a, b | a.length - b.length ] which is just the same as writing Collections.sort(someStrings, [ a, b | a.length - b.length ]) Since you can leave out empty parentheses for methods which get a lambda as their only argument, you can reduce…

Now I know why there are two (three) version for coding this timer business. Thanks Rich!

I installed the designer again; just to make sure there is no syntax error in my rule, and there are no red crosses in my rules (or elsewhere).

Should I just give it a rest – as in this is too hard?!
I have spent 6 hours reading the forum with related issues, and none of them got resolved (other than syntax errors)… is this a bug?