Why is my lab automation run failing and producing an error message?

Issue

• Lab automation run fails
• Error message "Failed to look up Column X: isMulti lookup step found Y result(s), but there are Z rows"

Environment

Generating an input file or processing an output file with processing steps on a lab automation run

Cause

The number of rows added by this lookup step doesn't match the number of rows already in the file, so the column can't be added. The number of rows in the file is defined by either:

• The source when generating an input file
• The file uploaded as the output file

Resolution steps

1. Confirm the amount of run fields match. For example, if your run transfers items from multiple input plates to multiple output plates, ensure there are an equal number of input and output plates, and that there are enough open wells in the output plates.
2. Review your run schema configurations for this lookup step in the input file generator/output file processor:
   • If the same value is used for all rows:
     • Check Consolidate all values into a single row on the second page of the lookup step definition
     • Leave Do not preserve relations between lookup steps checked
   • If some fields are empty or have multiple values per source of the lookup step:
     • Uncheck Do not preserve relations between lookup steps