ERROR_IS_SUBST_PATH - 146 (0x92)
The path specified is being used in a substitute.
Updated: Feb 21, 2026
Technical Meaning
The ERROR_IS_SUBST_PATH error code indicates that a path specified in an operation is currently being used as part of a substitute path. This typically occurs when the system detects an attempt to use a path that has already been substituted by another path or volume.
Error Details
This error is specific to operations involving paths and directories, particularly those related to file system substitution mechanisms such as drive letters or mount points. The error suggests that the specified path is part of a substitute path structure, which may be managed by the operating system for various purposes, including virtualization or redirection.
Usage Context
The ERROR_IS_SUBST_PATH error can arise in scenarios where an application attempts to perform operations on paths that are already being used as substitutes. For example, if a drive letter is mapped to a network share and an attempt is made to access the original path directly, this error might be returned.
Developer Interpretation
Developers should interpret this error code as indicating that the specified path is part of a substitute path structure managed by the operating system. This implies that direct operations on such paths may not be supported or could lead to unexpected behavior. Developers are advised to ensure that their applications handle paths correctly, especially when dealing with virtualized file systems.
Related Errors
- ERROR_PATH_NOT_FOUND (3): The specified path does not exist.
- ERROR_INVALID_DRIVE (21): An invalid drive specification was used.
- ERROR_BAD_NETPATH (67): A network path was not found or could not be reached.
FAQ
Q: What causes the ERROR_IS_SUBST_PATH error?
A: This error typically occurs when an attempt is made to use a path that has already been substituted by another path or volume. For example, if a drive letter is mapped to a network share and an operation is performed on the original path.
Q: How can I resolve this issue?
A: Ensure that your application correctly handles paths, especially when dealing with virtualized file systems. Verify that operations are being performed on the correct paths as managed by the operating system.
Summary
The ERROR_IS_SUBST_PATH error code indicates that a path specified in an operation is part of a substitute path structure managed by the operating system. Developers should be aware of this behavior and ensure their applications handle such paths appropriately to avoid unexpected issues.