I got this error when I go to Catalog > Products and select a filter.
I'm on Magento 2.2.6.
Magento says this bug is supposed to be fixed on 2.2.6 but clearly it's not.And unfortunately I do not have enough credibility to comment on this thread and ask what has to be changed to what.
Hoping this question will gain me some credibility hahaha.
Thanks!!!! :) :)