ERROR_LOST_WRITEBEHIND_DATA_NETWORK_SERVER_ERROR - 789 (0x315)
{Delayed Write Failed} Windows was unable to save all the data for the file %hs; the data has been lost. This error was returned by the server on which the file exists. Please try to save this file elsewhere.
Updated: Feb 21, 2026
Technical Meaning
The ERROR_LOST_WRITEBEHIND_DATA_NETWORK_SERVER_ERROR error, with the numeric code 789 or hexadecimal value 0x315, indicates that a delayed write operation failed. Specifically, Windows was unable to save all the data for the file on which the operation was performed due to an issue reported by the network server hosting the file.
Error Details
This error is typically encountered when attempting to save or modify a file over a network connection. The underlying mechanism involves delayed write operations, where changes are written to a temporary location before being committed to the permanent storage on the server. If this process fails for any reason, the data may be lost.
Usage Context
This error can occur in various scenarios involving file operations over a network, such as saving documents, editing files, or performing write-intensive tasks. It is particularly relevant when using network drives, shared folders, or cloud storage solutions that rely on delayed writes for performance optimization.
Developer Interpretation
Developers should interpret this error as an indication of a failure in the delayed write mechanism during file operations over a network connection. This can be due to various factors such as network issues, server-side errors, or limitations imposed by the network infrastructure. Developers are advised to handle such errors gracefully and provide appropriate feedback to users.
Related Errors
ERROR_WRITE_FAULT(0x7B)ERROR_DISK_FULL(0x702)ERROR_NETWORK_ACCESS_DENIED(0x51)ERROR_FILE_NOT_FOUND(0x3)
FAQ
Q: What does the ERROR_LOST_WRITEBEHIND_DATA_NETWORK_SERVER_ERROR mean?
A: This error indicates that a delayed write operation failed, resulting in data loss for the file on a network server.
Q: How can I prevent this error from occurring?
A: Ensure stable network connections and verify that the server hosting the file is functioning correctly. Implement retry mechanisms to handle transient errors gracefully.
Summary
The ERROR_LOST_WRITEBEHIND_DATA_NETWORK_SERVER_ERROR (789) is a generic error indicating a failure in delayed write operations over a network connection. Developers should interpret this error as an indication of potential issues with the network or server and implement appropriate handling mechanisms to ensure data integrity.