Microsoft Fabric Error:
No Delta Transaction Log Entries Were Found
What does this error mean?
Fabric Lakehouse cannot read a directory as a Delta table because the _delta_log folder is missing or empty.
Common causes
- 1Parquet files were copied directly to the table path (e.g., via azcopy or data pipeline) without converting them to Delta format
- 2Attempting to query a folder created by a Spark write before the Delta format was enabled (plain Parquet output)
- 3The _delta_log directory was accidentally deleted
- 4Using spark.read.parquet() and then registering the result as a table without converting to Delta
How to fix it
- 1Convert existing Parquet files to Delta format: CONVERT TO DELTA parquet.`<abfss-path-to-folder>`.
- 2Alternatively, use Delta write mode from scratch: spark.read.parquet('<path>').write.format('delta').save('<new-path>').
Beyond the docs
Common practitioner solutions not covered in the official documentation.
- 1Verify the _delta_log directory exists in the table folder using the Lakehouse Explorer or an ABFSS ls command
- 2If the Delta log was accidentally deleted, restore it from the Recycle Bin in the Fabric portal if available
- 3When copying data into Lakehouse, always write via Delta API or pipeline Copy Data activity — avoid direct file copy to the Tables area