ERROR_LOST_WRITEBEHIND_DATA - 596 (0x254)
{Delayed Write Failed} Windows was unable to save all the data for the file %hs. The data has been lost. This error may be caused by a failure of your computer hardware or network connection. Please try to save this file elsewhere.
Updated: Feb 21, 2026
Technical Background
The ERROR_LOST_WRITEBEHIND_DATA error code (596, 0x254) is a specific file system error that indicates a failure in the delayed write mechanism. This error typically occurs when the operating system fails to save all data for a file due to hardware or network issues.
Error Details
The ERROR_LOST_WRITEBEHIND_DATA error message, {Delayed Write Failed}, informs users that Windows was unable to save all the data for a specific file. The message also mentions that the data has been lost and suggests that this issue may be caused by hardware or network problems.
Common Causes
- Hardware Failure: Issues with storage devices can lead to delayed write failures, as the system might not have enough time to complete the write operation before the device becomes unavailable.
- Network Connectivity Problems: If a file is being written over a network connection and the connection drops, data may be lost due to the inability to complete the write operation in a timely manner.
Real-World Context
This error can occur when performing large writes or when there are intermittent connectivity issues. It is particularly common during operations that involve writing significant amounts of data to files, such as saving documents or transferring large files over a network.
Is This Error Critical?
The criticality of this error depends on the context in which it occurs. Losing unsaved data can be detrimental, especially if the data is not recoverable. However, in some cases, the system might attempt to recover the lost data automatically, reducing the impact of the error.
How to Diagnose
Reviewing Operation Context
- Check Storage Devices: Ensure that all storage devices are functioning properly and have sufficient capacity.
- Verify Network Connectivity: Confirm that network connections are stable and reliable, especially when writing files over a network.
Validating Parameters
- File Operations: Verify that the file operations being performed are correct and do not exceed any system limits or constraints.
Confirming Object Types
- File vs. Directory Operations: Ensure that the operation is appropriate for the type of object (file or directory) being manipulated.
How to Resolve
Correct Parameter Usage
- Ensure Proper File Handling: Use correct file handling methods and ensure that all parameters are valid and within acceptable ranges.
Adjust Operation Context
- Retry Operations: If network connectivity issues are suspected, retry the operation after ensuring a stable connection.
Restore Data
- Data Recovery Tools: Utilize data recovery tools if necessary to attempt restoring lost data.
Retry Operation with Valid Inputs
- Validate Input Data: Ensure that all input data is valid and does not exceed any system limits or constraints before performing file operations.
Developer Notes
Developers should be aware of the potential for delayed write failures, especially when dealing with large files or networked storage. Implementing robust error handling and retry mechanisms can help mitigate the impact of this error.
Related Errors
- ERROR_WRITE_FAULT: This error occurs when a write operation fails due to a fault in the file system.
- ERROR_DISK_FULL: This error indicates that the disk is full, which could contribute to delayed write failures if the system cannot complete writes due to lack of space.
FAQ
Q: What does ERROR_LOST_WRITEBEHIND_DATA mean?
A: It means that Windows was unable to save all the data for a file and the data has been lost, possibly due to hardware or network issues.
Q: How can I prevent this error from occurring?
A: Ensure stable storage devices and network connections, validate parameters, and handle operations correctly to minimize the risk of delayed write failures.
Summary
The ERROR_LOST_WRITEBEHIND_DATA error code (596, 0x254) is a specific file system error that indicates a failure in the delayed write mechanism. This error can be caused by hardware or network issues and can result in data loss. Developers should implement robust error handling and ensure proper operation context to mitigate this issue.