At a specific layer you couldn't check a checkbox and the form was
invalid (a token was not part of the form therefore it was invalid).
However the number of checked checkboxes was the hint: If they are some
handful higher, the form wasn't saved.
The PHP-parameter for that is the "max_input_vars". If you experience
that problem, put it to a higher value. In my php.ini it was commented
out and I set it to 2000. Depends a bit on the number of layers my WMS
HTH and HAND
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