Azure Databricks Workflow Debugging

I'm encountering an 'Analysis Exception' error in my Azure Databricks workflow, specifically failing to merge fields 'sales_val'.
My lead wants me to debug this issue, find the root cause, and implement a fix.

Also need assistance in checking the health report.

Project Requirements:
- Work with multiple data sources: Azure Data Lake, SQL Database, Blob Storage, Databricks, Pyspark.
- Focus on Data Transformation issues, particularly joining or merging fields.

Ideal Skills:
- Experience with Azure Databricks and Pyspark.
- Strong debugging and problem-solving skills.
- Familiarity with data health reports and metrics.

Urgent assistance needed.