Error: Null Pointer Exception in Joiner Node

[Diego_Koga]

Hello Everyone!

I’ve been running a flow where I’ve met an error “Execute failed: (“NullPointerException”): null” being thrown by the Joiner Node.

I’m only using “id_pedido” as key.

I already tried:

• Filtering missing values
• Recreating the node
• Tried joining with other keys

This is an example of what I’m trying to join from the group by with the joiner:

The node runs up to around 8% and throws the error…

Has anyone ever met this issue?

[Diego_Koga]

I just found what it was!

It was caused by a column (not the one used as join key) that had mixed types.
Treating them and also applying a Missing Value node solved the problem

[hotzm]

Hi @Diego_Koga,

glad to hear that you could work around the problem.

I am unable to reproduce it, but would like to understand why it happens in order to fix what sounds like a bug.

What were the types that made up the mixed-type column? Could you post your node’s configuration (with column names obfuscated) or a small reproduction workflow?

Best,
Manuel