Hello
when i try to add new item to tree i get "Error: assertion failed in ItemFileWriteStore message=assertion failed in ItemFileWriteStore" this error.
and this behavior is inconsistent. sometimes newitem gets added correcltly, and sometimes it gives error.
Any help appreciated, Thanks in advance

Check your store item data
I used to get inconsistent asserts with IFRStore and it was always to do with the content of the json data I was passing to the store. This would seem to correlate with the fact that you only get the asserts intermittently, i.e. if there was a problem with the store then it would be more likely to fail consistently.
Check that content of the json data that you are trying to add to the store - are all the mandatory fields set, e.g. the fields that correspond to the 'searchAttr' and 'identifier' properties of the store.
You might have to set breakpoints in the addItem function of the store and trace to see where the assert is fired.
Also check the _loadFinished property of the store and the _allItems (which should get populated when load is complete). If _loadFinished is false, it is usually a sign that the data passed could not be successfully parsed and added.
getting error after deleting any tree node
i am getting error after deleting tree node.