Unlinked filters raise error on PDF download

Very obscure issue, but we’ve found that if you have a dashboard with tiles that include merge queries, if you add a filter and do not actually have it do anything (i.e. don’t set what fields it should update) then when you try to export to PDF you get the following error:

Making a merge result with filters requires the filters array to be the same length as the number of source queries

This is not a very helpful error to receive, especially as I didn’t personally make this dashboard. I assume there are other conditions that could raise this error but again it’s not clear what these might be. Could this either be explained better, or a help topic made to explain what this means? Thanks.