What causes DF-Delimited-ColumnDelimiterMissed?

The 'Column delimiter' field in the delimited text dataset Format settings is empty or was set to 'None'. A dataset was created via import or copy and the delimiter auto-detection failed, leaving the property unset. The column delimiter was removed during a dataset edit, breaking existing data flow references

How do I fix DF-Delimited-ColumnDelimiterMissed?

Open the delimited text dataset in ADF Studio and go to Format settings tab.. Set the 'Column delimiter' to the character used in your files — comma (,) for CSV, tab (\t) for TSV, pipe (|) for pipe-delimited, or a custom single-character delimiter.. If unsure, open a sample file from the source storage in a text editor to visually inspect the delimiter used between fields.. Save the dataset and re-run the data flow to confirm the error is resolved.

Medium severitydata flow

Power BI Refresh Error:
DF-Delimited-ColumnDelimiterMissed

What does this error mean?

The ADF Mapping Data Flow delimited text dataset has no column delimiter configured. A column delimiter (comma, tab, pipe, etc.) is required for the data flow to correctly parse or write delimited files.

Common causes

1The 'Column delimiter' field in the delimited text dataset Format settings is empty or was set to 'None'
2A dataset was created via import or copy and the delimiter auto-detection failed, leaving the property unset
3The column delimiter was removed during a dataset edit, breaking existing data flow references

How to fix it

1Open the delimited text dataset in ADF Studio and go to Format settings tab.
2Set the 'Column delimiter' to the character used in your files — comma (,) for CSV, tab (\t) for TSV, pipe (|) for pipe-delimited, or a custom single-character delimiter.
3If unsure, open a sample file from the source storage in a text editor to visually inspect the delimiter used between fields.
4Save the dataset and re-run the data flow to confirm the error is resolved.

Frequently asked questions

How do I determine which delimiter my files use?

Open a sample in a text editor and look for the character separating column values. CSV uses comma, TSV uses tab, pipe-delimited uses |.

Can the delimiter be more than one character?

No — ADF delimited text format only supports single-character delimiters. Pre-process files with a multi-character separator or use a custom transformation.

Does this error affect the source, the sink, or both?

A missing delimiter on a source means the file cannot be parsed into columns. A missing delimiter on a sink means the output cannot be written with separators. Both cause this error.

Official documentation: https://learn.microsoft.com/en-us/azure/data-factory/data-flow-troubleshoot-guide