Transform map field mapping error: source field missing

The external data source schema changed and removed or renamed a field that the transform map still references in its field mappings. (high likelihood)

The import set table was manually modified or recreated without preserving all original column definitions that the transform map expects. (high likelihood)

A typo or case sensitivity mismatch exists in the transform map field mapping configuration where the source field name doesn't exactly match the import set column name. (medium likelihood)

The wrong import set table is being used with the transform map, causing field name mismatches between expected and actual source columns. (medium likelihood)

Import set table columns were deleted during cleanup operations without updating the corresponding transform map field mappings. (low likelihood)

Step 1: Navigate to System Import Sets > Administration > Transform Maps and locate the failing transform map from the error log details.

Step 2: Open the transform map and click on the Field Maps related list to review all configured source field mappings.

Step 3: Navigate to System Import Sets > Import Set Tables and open the import set table referenced by the transform map to verify which columns actually exist.

Step 4: Compare the field mapping source field names with the actual column names in the import set table, checking for exact matches including case sensitivity.

Step 5: For missing source fields, either delete the obsolete field mapping if the field is no longer needed, or update the source field name to match the correct column name in the import set table.

Step 6: If the source data schema has changed significantly, use the Auto Map Matching Fields feature on the transform map to automatically recreate field mappings based on current import set table structure.

Step 7: Test the transform map by running a sample import or using the Test Transform function to verify all field mappings resolve correctly.

Step 8: Monitor subsequent import operations through System Import Sets > Import Set Run History to confirm the error is resolved.