initial warning message when drag the layout

[lidaof]

I am trying to drag and drop the layout and keep updating the weight of each tabset/row, the resize event listener works fine but every first time when I drag it gives me a warning message...other than that everything works fine.

jsfiddle link and warning message:

Warning: Cannot update during an existing state transition (such as within `render`). Render methods should be a pure function of props and state.
    at e (https://rawgit.com/caplin/FlexLayout/demos/demos/v0.30/flexlayout.js:1:58652)
    at Main (<anonymous>:53:9)

is there a way to avoid the warning?

thanks in advance.