Resolving "Unable to Read Mapping File" Error in DX

Overview

This article explains how to troubleshoot and fix the "Unable to Read Mapping File" error in DX, typically caused by unfinished mappings in the enumerations section.

1. Understanding the Error

✔ Error Message: "Unable to read mapping file."
✔ Possible Causes:

• The mapping file was reused from a different ReqIF file and does not match the current import structure.

• Unfinished mapping rows in the enumerations section, where some fields are neither mapped nor disabled.

• Corrupt or improperly formatted mapping file.

✔ Impact:

• The DX import fails, blocking migration.

• Users cannot proceed with the mapping process.

2. How to Fix the Issue

A. Verify That the Mapping File Matches the ReqIF File

✔ If the mapping file was reused from another import, regenerate a new mapping file specifically for the current ReqIF.
✔ To do this:

1. Start a new import process in DX.

2. Select the correct ReqIF file.

3. Generate a fresh mapping file and configure mappings accordingly.

B. Check for Unfinished Mappings in the Enumerations Section

✔ Open the mapping file in DX and look for incomplete mapping rows.
✔ Ensure that:

• Each enumeration option has a mapped picklist option, or

• The row is disabled if it is not needed.

✔ Example Fix:

• Before (Error-Prone):

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  Enumeration: "Verification Status" → [No selection]

• After (Corrected):

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  Enumeration: "Verification Status" → "Not Started, In Progress, Completed"

✔ If an enumeration is not required, disable it.

C. Ensure DX Can Access the Mapping File

✔ If the mapping file is stored in a restricted folder, move it to a location with proper access permissions.
✔ Avoid storing the file in network drives or OneDrive, which may cause access issues.

3. Best Practices to Prevent Mapping File Errors

✅ Always generate a fresh mapping file for each new ReqIF import.
✅ Ensure all enumeration fields are either mapped or disabled.
✅ Save mapping files in an accessible directory (avoid network storage issues).
✅ Review mappings before proceeding with the import.

4. Conclusion

• Mapping file errors usually stem from mismatched ReqIF structures or incomplete mappings.

• Generating a new mapping file and ensuring proper enumeration mappings resolves the issue.

• Proper file storage and access settings prevent read errors in DX.