terraform_plan-failure.txt

$ terraform plan
2020/01/09 16:47:01 [INFO] Terraform version: 0.12.19
2020/01/09 16:47:01 [INFO] Go runtime version: go1.13.5
2020/01/09 16:47:01 [INFO] CLI args: []string{"/usr/local/bin/terraform", "plan"}
2020/01/09 16:47:01 [DEBUG] Attempting to open CLI config file: /Users/local_user/.terraformrc
2020/01/09 16:47:01 [DEBUG] File doesn't exist, but doesn't need to. Ignoring.
2020/01/09 16:47:01 [INFO] CLI command args: []string{"plan"}

Error: Variables not allowed

  on providers.tf line 20, in provider "ns1":
  20:     version                = var.ns1_provider.provider_version

Variables may not be used here.