TL;DR

Grant IntelliJ IDEA OAuth app access to your GitHub organization under Authorized OAuth Apps in your GitHub profile settings. Once approved, PRs show up normally in IntelliJ.

Detailed Answer

This error is not about Git itself (fetch/push/pull work fine) but about how IntelliJ’s GitHub plugin talks to the GitHub GraphQL API to fetch pull requests. For private repositories inside an organization, the plugin needs explicit OAuth authorization to access the org’s repos otherwise fails with an error like mentioned in the question.

Solution

1. Go to your GitHub profile in the browser:

   • Profile → Settings → Integrations → Applications → Authorized OAuth Apps

2. Find IntelliJ IDEA (or JetBrains IDE Integration) in the list.

3. Click it, and grant access to your organization where your repo belongs to.

4. Restart IntelliJ IDEA and re-open the Pull Requests tool window.

After granting org access, the plugin can query the repo via GraphQL and the PR list loads correctly.

Why this happens

• Git operations use your local credentials/SSH keys, so they work fine.

• The PR tool window uses GitHub’s GraphQL API via OAuth.

• If the org restricts third‑party app access, IntelliJ must be explicitly authorized for that org.