Preview not loading after trying to join datasets

So I am getting this error where suddenly all my previews after the data sets to include joins and transforms no longer load.

A couple questions to help debug this:

  • Is this only happening for joins or is this also happening for any transform after the input?
  • How large are your inputs? Are the rows exploding and the join is just taking a really long time to calculate?
  • Is this a batch pipeline or lightweight?