Thanks David for your effort!
It is not so bad for me now, since it works without masonry and since I now know that the error is triggered by Adsense. Also I have learned a little bit about the mutation observer π
I am rather shocked what Google does so easily, since in some scenarios errors are pre-programmed.
I think it’s good that you asked Tom. Maybe he has an idea. If there is no solution for it, it is also OK.
Thanks again for your effort. I really appreciate it!