What does Windows error code 15156 (ERROR_PRI_MERGE_MAIN_PACKAGE_REQUIRED) mean?

ERROR_PRI_MERGE_MAIN_PACKAGE_REQUIRED

Packages for a PRI file merge must include one main package.

ERROR_PRI_MERGE_MAIN_PACKAGE_REQUIRED is Windows status 15156 (0x00003B34) associated with a PRI merge set with no main package.

Likely impact: Resource-only inputs cannot establish the canonical package context.

Typical causes

• only resource-package PRI files were selected.
• the main build artifact was omitted.
• artifact filtering excluded the neutral package.
• the main PRI failed earlier generation.

Troubleshooting steps

1. Verify that exactly one main-package PRI supplies identity, schema, and default resource maps.
2. Collect input package roles and expected main package path.
3. Correlate build manifest and generation logs with MakePri command line, input PRI inventory, package identities, schemas, file hashes, output path, tool version, and the first detailed merge diagnostic.

Useful evidence

• Collect expected path.
• Collect schema presence.
• Collect artifact filter result.

Recovery and retry

Generate or include the authoritative main-package PRI before adding resource packages.

Related errors

ERROR_PRI_MERGE_RESOURCE_PACKAGE_REQUIRED means the main exists but no resource package is present; this code lacks the main package

Example

A localization pipeline collects only language packages. Adding the neutral main package gives merge the schema and identity it needs.

References

• Microsoft: exact Win32 system error range
• Microsoft: MakePri.exe command options
• Microsoft: Package Resource Index files