Error
Error Code:
157
MongoDB Error 157: Downgrade Repair Required
Description
Error 157, 'Can Repair To Downgrade,' indicates that a MongoDB instance cannot be downgraded to an older version without first performing a special repair operation. This is typically required when the data files contain features or formats introduced in a newer version that are incompatible with the target older version, often related to the Feature Compatibility Version (FCV) setting.
Error Message
Can Repair To Downgrade
Known Causes
3 known causesAttempting Direct Downgrade
This error occurs when a user tries to start a MongoDB instance with an older binary version on data files created or modified by a newer version without explicit preparation.
Higher Feature Compatibility Version (FCV)
The current Feature Compatibility Version (FCV) of the replica set or sharded cluster is set to a version higher than the target MongoDB version for the downgrade.
Incompatible Data File Formats
The existing data files contain storage engine features or on-disk formats that are not supported by the older MongoDB binary version being used for the downgrade attempt.
Solutions
Coming SoonDetailed step-by-step solutions for this error are being prepared. In the meantime, try these general troubleshooting tips:
General Troubleshooting Tips
- Check the error message carefully for specific details
- Review recent changes that might have caused the error
- Search for the exact error code in the official documentation
- Check log files for additional context
- Try restarting the application or service