What does Windows error code 14021 (ERROR_SXS_DUPLICATE_DLL_NAME) mean?

 
Previous Next
ERROR_SXS_PRIVATE_MANIFEST_CROSS_PATH_WITH_REPARSE_POINT ERROR_SXS_DUPLICATE_WINDOWCLASS_NAME

ERROR_SXS_DUPLICATE_DLL_NAME

ERROR_SXS_DUPLICATE_DLL_NAME means that two components referenced directly or indirectly by the active manifest graph contain files with the same DLL name. Windows cannot choose one safely when both assemblies contribute the same named binary to the active side-by-side context.

How to investigate

  • Use the dependency trace to identify both assemblies that contribute the duplicate DLL name.
  • Correct the package so the application graph selects one compatible assembly instead of embedding competing copies.
  • Do not delete a DLL only by filename until its manifest ownership and dependent modules are understood.

This is a conflict in the active assembly graph, not a normal DLL search-order decision.

Microsoft: side-by-side assemblies


Looking for a different code? Search another status or error code.