I'm not sure about journals of negative results (though I ran across this effort: https://www.negative-results.org https://www.negative-results.org). However, I

I'm not sure about journals of negative results (though I ran across this effort: https://www.negative-results.org https://www.negative-results.org). However, I'm aware of, at least, one workshop on negative results. That was the 2015 ERROR workshop in e-science domain. Please see https://press3.mcs.anl.gov/errorworkshop https://press3.mcs.anl.gov/errorworkshop for details.