ERROR_BAD_DEV_TYPE - 66 (0x42)
The network resource type is not correct.
Updated: Feb 21, 2026
Technical Background
The ERROR_BAD_DEV_TYPE error code is encountered when a network resource type does not match the expected or supported type. This can occur in various contexts, such as file system operations, device management, or network protocol handling.
Error Details
- Error Name: ERROR_BAD_DEV_TYPE
- Numeric Code: 66 (0x42)
- Hex Code: 0x42
- Short Description: The network resource type is not correct.
This error typically indicates that the system has attempted to perform an operation on a device or resource of an incorrect type, leading to a failure. It can be encountered in scenarios where specific types of devices or resources are expected but not found or recognized correctly.
Common Causes
- Invalid Parameter Values: The parameter passed to the API or function does not specify a valid network resource type.
- Incorrect Object Type: The object being accessed is of an unexpected type, such as attempting to treat a file as a directory or vice versa in a network context.
- Exceeding Limits: The system has encountered a limit on the number of resources that can be handled simultaneously.
Real-World Context
This error can occur when performing operations on networked devices or resources, such as mounting a network drive, accessing shared files, or managing network connections. It is particularly relevant in scenarios where specific types of network resources are expected but not present or recognized correctly.
Is This Error Critical?
The criticality of this error depends on the context and the operation being performed. In some cases, it may be a minor issue that can be resolved by correcting the parameters or object type. However, in other scenarios, it could indicate a more serious problem with the network configuration or device management.
How to Diagnose
- Review Operation Context: Ensure that the operation context is correct and matches the expected environment.
- Validate Parameters: Verify that all parameters passed to the API or function are valid and correctly specify the resource type.
- Confirm Object Types: Confirm that the object being accessed is of the expected type. For example, ensure that a directory is treated as a directory and not a file.
How to Resolve
- Correct Parameter Usage: Ensure that all parameters passed to the API or function are correct and specify the appropriate resource type.
- Adjust Operation Context: If the operation context is incorrect, adjust it to match the expected environment.
- Restore Data: In cases where data corruption may have occurred, restore the data from a backup if available.
Developer Notes
Developers should ensure that all network operations are performed with correct and valid parameters. This includes specifying the appropriate resource types when interacting with networked devices or resources. Additionally, error handling should be robust to account for potential mismatches in resource types.
Related Errors
- ERROR_BAD_NETPATH (123): Indicates an invalid network path.
- ERROR_INVALID_PARAMETER (87): General error indicating that one or more parameters are incorrect.
- ERROR_NO_SUCH_DEVICE (19): The specified device could not be found.
FAQ
Q: What does the ERROR_BAD_DEV_TYPE error mean?
A: It indicates that a network resource type is not correct, meaning an operation was attempted on a resource of an unexpected or unsupported type.
Q: How can I prevent this error from occurring?
A: Ensure that all parameters passed to API functions are valid and correctly specify the expected resource types. Validate object types before performing operations.
Q: Is this error critical for system stability?
A: The criticality varies; it may be a minor issue or indicate a more serious problem with network configuration or device management.
Summary
The ERROR_BAD_DEV_TYPE error code indicates that an operation was attempted on a resource of the incorrect type. This can occur in various contexts, such as file system operations, device management, or network protocol handling. Proper parameter validation and correct object types are crucial to avoid this error.