# Expected Diagnosis: changefeed-stops-on-row-encoding-error

The expected result should converge on the case-specific mechanism below while
keeping conclusions bounded by the collected evidence.

## Expected conclusion

Debezium DDL encoding mutated shared table metadata, changing a DEFAULT NULL datetime definition into an invalid non-null default. Later DML encoding consumed the polluted metadata and attempted to encode an empty or nil value as datetime. Restarting or cloning the changefeed rebuilds metadata temporarily; the formal fixed TiCDC build is the durable solution.

## Required evidence chain

- Do not classify the valid NULL source value as corrupt application data.
- Identify Debezium DDL encoding as the path that mutates shared table metadata.
- Explain how later DML encoding reads the polluted datetime default and emits the <nil> error.
- Recommend restart or clone for temporary recovery and upgrade to the fixed formal build.