# S12003 {#S12003}

## Error Code {#error_code .section}

S12003

## Error Message {#error_message .section}

`Failed to serialize level file {BlockType}: filepath_=<xxx>. Please check your disk or file system. RefId: S12003`

`Failed to deserialize level file {BlockType}: filepath_=<xxx>. Please check your disk or file system. RefId: S12003`

## Probable Causes {#probable_causes .section}

These errors occur when there is a failure in writing to a file during the flush \(serialization\) or merge \(deserialization\) process. The system will log the error and roll back the flush/merge operation.

Deserialization failures may be caused by:

-   Compatibility issues, such as using an older version server to read data written by a newer version server.

-   Disk or file system failures.

-   Corruption of level files.


## Solutions {#solutions .section}

-   Check if the disk is full or damaged.
-   Check if there are any issues with the file system.

**Parent topic:**[Error Code Reference](../../Troubleshooting/ErrorCode.md)

