GitLab "configuration is invalid: variable" Errors

GitLab rejected the config because a variables entry is malformed - the wrong type, an invalid name, or a value that is not a string or expandable scalar.

What this error means

Validation fails naming the variables block: a value that should be a string is a map or list, or a variable name uses characters GitLab does not allow. No pipeline runs until it is fixed.

gitlab-ci

This GitLab CI configuration is invalid:
variables config should be a hash of key-value pairs, value can be a hash

Common causes

Non-string or malformed value

A variable value given as a raw list, or a nested map missing the value: key when using the descriptive form, fails the schema.

Invalid or reserved variable name

Variable names must match GitLab's allowed pattern. A name with spaces, leading digits, or an illegal character is rejected.

How to fix it

Use string values (or the descriptive hash form)

.gitlab-ci.yml

variables:
  DEPLOY_ENV: "staging"
  TIMEOUT: "30"
  REGION:
    value: "us-east-1"
    description: "Deployment region"

Fix the variable names

Use only letters, digits, and underscores; do not start a name with a digit.
Quote numeric or boolean-looking values so they stay strings.
Re-validate in the Pipeline Editor after correcting names and types.

How to prevent it

Always quote numeric and boolean variable values.
Keep variable names alphanumeric with underscores.
Validate the variables block in the editor before merging.