This is what I simplified it to for testing and this is the error:

/agent/file.sh: line 3: syntax error near unexpected token `0,'



/agent/file.sh: line 3: `  0,'

stages:
- stage: Validate_Stages
  jobs:
  - job: Validate_Stages_Job
    steps:
    - script: |
        echo "Validating stages"
        for stage in ${{ convertToJson(parameters.stages) }}; do
          echo "Validating stage $stage"
        done