@gaj98307 I would recommend you re-posting this in the Designer Cloud Discussion Board:
Alteryx Designer Cloud Discussions - Alteryx Community
- Switch output to CSV temporarily -> run.
--> If it succeeds: focus on Excel output configuration.
- Remove/disable Pivot/Unpivot/Join/Union steps -> run
--> If the error disappears: the mismatch is in that operator; re-validate keys/columns.
- Turn off strict schema on any steps/output -> run.
--> If it succeeds: re-align schema or add a schema enforcement step right before the writer.

