What does Windows error code 182 (ERROR_INVALID_ORDINAL) mean?

ERROR_INVALID_ORDINAL

What ERROR_INVALID_ORDINAL means

ERROR_INVALID_ORDINAL is Win32 system error code associated with the documented message: “The operating system cannot run %1.” The significant condition is that a module import names an export ordinal that the loaded dependency does not provide.

Likely causes

• the wrong version of a DLL was found first in the search path
• an application imports by ordinal and the vendor changed the export table
• a damaged or replaced dependency has an incomplete export directory

Troubleshooting steps

1. Record the exact executable and dependency paths selected by the loader
2. Inspect the importing module’s ordinal and the dependency’s export table
3. Restore the matching application/DLL set and retest without PATH or side-by-side redirection changes

Code-specific investigation notes

Ordinal imports are intentionally compact but bind the application to a particular export-table layout. Two DLLs can share a name and version-looking filename while exposing different ordinals.

Loader search order matters: application directory, side-by-side activation, system directories, and PATH can select different modules. Capture the actually loaded path rather than the path you expected.

Do not “fix” the problem by renaming an arbitrary DLL into place. Matching architecture and exported ordinal semantics are both required.

Difference from related errors

ERROR_PROC_NOT_FOUND usually concerns a missing exported name; it is specifically about an ordinal-based import that is absent or invalid.

References

• Microsoft: System error codes 0–499