Error
Error Code:
201
MongoDB Error 201: Index Key Construction Failure
Description
Error 201 indicates that MongoDB was unable to construct index keys for a document. This often occurs during write operations (insert, update) or when building an index, usually due to invalid data types, values exceeding limits, or other data integrity issues within the indexed field.
Error Message
Cannot Build Index Keys
Known Causes
3 known causesMismatched Data Type
A document's field intended for indexing contains a value of an incompatible data type for the defined index.
Value Exceeds Index Limits
The value of a field targeted for indexing is too large or outside the valid range for the specific index type.
Corrupted BSON Data
The BSON representation of the document or its field is malformed, preventing key extraction.
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