I had exactly this same problem today.
In my case, it had something to do with the qWidth and qHeight (as erik.wetterberg mentioned). I had used 10 as qWidth and 10,000 as qHeight, so the total possible number of cells was 100,000. Apparently, 10,000 is the limit for cells. Now, the data I was testing with didn't actually have over 10,000 cells, but it still seemed to make Qlik . I reduced qHeight to 1000 and it seemed like Qlk was .
As Erik also mentioned (he answers all my questions, by the way), changing the source code for initial properties doesn't seem to have an effect on the original Qlik object, you have to delete it and recreate. But, if you are creating a new extension, such things should be expected.