# Terraform: Error: Module not installed — This module is not yet installed. Run "terraform init" to install all modules required by this configuration

**Code:** `Module not installed` · **Category:** Terraform · **Seen on:** Terraform

A module block references a module that hasn't been downloaded to `.terraform/modules`.

## Meaning

Run `terraform init` (or `terraform get`) after adding or changing a `module` block or its version/source. CI should init every job. For local paths, verify the relative `source = "./modules/x"` exists. `terraform init -upgrade` refreshes versions.

## Common causes

- New module added without init
- Source/version changed
- `.terraform` missing/cached stale in CI
- Wrong local path
- Registry module unavailable

## Quick fix

1. `terraform init` (or `terraform get`)
2. Check `source` path/URL/version
3. `terraform init -upgrade` after version changes

## Detailed fix by platform

### Terraform

1. `terraform init && terraform validate`

## How to diagnose

1. **Init** — Run after the change?
2. **Path** — Exists?
3. **Version** — Resolvable?

---
Source: [WhatIsMyError](https://whatismyerror.com/errors/terraform/module-not-installed-run-terraform-init)