StackOverflow Error - FeatureLookup & fs.create_training_set

[lndlzy]

When trying to utilize feature_lookup on at least 2 feature tables and trying fs.create_training_set, I get a stackoverflow error. Can anyone help me understand why this happens? This hasn't happened before but now I get this error and I am unable to resolve this considering that my code works properly before. 

Thank you!

[lndlzy]

When I used one feature table with around 500 features, it worked. I was actually planning on just passing multiple feature tables for featurelookup and then somewhat do the selection and preprocessing from there however I think it does not work. Do you have any suggestion as to a workaround? Like maybe would it be just the same if I just join those feature tables?