Failed to create changeset (configuration, not infrastructure)

WHAT IT MEANS

The common shapes

• Unable to locate credentials — no credential source in this environment: the CI job never ran its auth step, or the profile is not set.
• Parameters: [Name] must have values — a template parameter with no default and no supplied value, often after adding a parameter without updating samconfig.toml or the pipeline.
• Error: Failed to create changeset with a specific reason attached — read the reason; when it matches a sharper failure (quota, schema, S3 access), that failure is the real page to follow.

TRIAGE

How to triage it

1. Check what credentials this environment resolves (read-only):

   aws configure list
   aws sts get-caller-identity

2. Compare declared parameters against supplied ones — the template's Parameters: block versus parameter_overrides in samconfig.toml and any --parameter-overrides flags.
3. Re-read the full reason line - this family is a wrapper, and the text after the colon usually names which specific page on this index actually applies.

AUTOMATE THE TRIAGE

Diagnose this automatically

SAM Doctor reports this family at medium confidence and deliberately steps aside whenever a sharper rule matches the same log - the quota, schema, artifact, and S3 rules all outrank it. Runs locally; no AWS access, no log upload.

python -m pip install sam-doctor
sam-doctor diagnose deployment.log --format markdown

RELATED

Related errors

• The security token is expired — when credentials exist but have aged out.
• InvalidSamDocumentException — the schema-validation reason this wrapper often carries.
• Template exceeds a quota — another specific reason hiding behind the generic wrapper.