Codex Diff Says "Oops"? Review Changes Safely

If the Codex IDE extension Diff or full Review tab in VS Code shows "Oops, an error has occurred" and then "No diff available", do not reset your repository or delete extension state. First verify the changes with Git, then review them through the inline Codex card or VS Code Source Control. Current reports show that the full editor-diff-page can crash while the underlying files, inline diff, native VS Code diff, and git diff remain healthy.

As of July 27, 2026, the main OpenAI report is still open. The safest recovery is therefore a trustworthy review path, not an unverified repair to the extension bundle.

Prerequisites

Before troubleshooting:

• save any open editor buffers;

• open the repository folder that Codex edited;

• use a terminal in that repository;

• record your VS Code and Codex extension versions;

• keep the Codex conversation open if its inline Review changes card still works.

This guide applies when Codex made file changes but its full Review page fails. It does not apply when Git itself cannot find a repository, the files were never written, or the entire Codex sidebar is unavailable.

If files may actually be missing rather than hidden by the viewer, preserve the repository first and follow the recovery boundaries in How to Prevent Codex from Deleting Files.

Step 1: Prove the Repository and Changes Still Exist

Run:

git rev-parse --show-toplevel
git status --short
git diff --stat

Expected result:

• git rev-parse prints the repository root;

• git status --short lists modified, staged, or untracked files;

• git diff --stat summarizes unstaged changes to tracked files.

If git status --short is empty, the Review page may be correct: there may be no working-tree change left to show. Check the current commit and recent history before assuming the viewer lost work:

git log -3 --oneline

Do not run git reset --hard, git clean, or delete the repository to make the viewer refresh. Those commands can destroy the evidence you are trying to review.

Step 2: Inventory Unstaged, Staged, and Untracked Work

One command does not show every kind of change. Run all three:

git diff --
git diff --cached --
git ls-files --others --exclude-standard

Expected result:

• git diff -- shows tracked changes not yet staged;

• git diff --cached -- shows changes already staged;

• git ls-files --others --exclude-standard lists untracked files.

An untracked file does not appear in a normal git diff, so an empty diff alone does not prove that Codex created nothing.

For a large change, start with filenames and status:

git diff --name-status
git diff --cached --name-status

Then review one path at a time:

git diff -- path/to/file
git diff --cached -- path/to/file

Step 3: Use the Inline Codex Diff

Return to the Codex conversation and open its inline Review changes card instead of the full editor tab.

Expected result: the inline renderer shows the changed files even though the full Review page still displays the error boundary. OpenAI issue #35362 reproduced exactly this split: inline review worked while the standalone full page crashed.

If the inline card also fails, continue with VS Code's native Source Control view.

Step 4: Review Through VS Code Source Control

Open Source Control:

• macOS: Control+Shift+G;

• Windows or Linux: Ctrl+Shift+G;

• or select the Source Control icon in the Activity Bar.

Select each file under Changes or Staged Changes. VS Code opens its native side-by-side or inline diff against the committed version.

Expected result: each tracked change opens in the native diff editor. Untracked files appear as new files and should be reviewed directly.

Git remains the source of truth for the working tree, and VS Code's Source Control view uses the same repository state as the command line. A crash in the Codex webview does not erase that state.

Step 5: Try the Non-Destructive Refresh Once

After preserving and reviewing the changes:

1. Open the Command Palette.

2. Run Developer: Reload Window.

3. Check the Codex extension for an update.

4. Reopen the same conversation and full Review page.

If the full Review page still fails, stop repeating reloads or reinstallations. Reports on extension builds 26.721.30844 and 26.721.41059 show that reloads, restarts, and reinstalls often leave this route-specific failure unchanged.

The OpenAI issues identify a recurring exception:

Thread context is unavailable for non-thread routes
editor-diff-page error boundary

That points to the standalone viewer, not to a corrupt Git working tree.

Step 6: Decide Whether to Roll Back the Extension

Most users can keep working with the inline, native VS Code, and Git review paths. That avoids pinning an older extension.

If the full Codex Review page is essential:

1. Open the Codex extension page in VS Code.

2. Select the extension gear menu.

3. Choose Install Another Version.

4. If available, install 26.715.61943.

5. Temporarily disable automatic updates for that extension.

6. Reload VS Code and open the full Review page again.

A July 26 issue comment reported that version as working, with 8 visible reactions. Treat it as a user-reported workaround, not an OpenAI guarantee. Re-enable updates and move to a current build after the matching OpenAI issue confirms a fix. Do not edit minified files inside the installed extension: one diagnostic patch isolated the problem, but extension updates overwrite it and the patch is not a supported repair.

When to Stop Using the Workaround

Retest after the matching OpenAI issue reports a fix or VS Code offers a newer Codex extension build. Re-enable automatic updates, install the current version, and open a full Review page in two small repositories.

The workaround is no longer needed when the full Review page renders twice, the inline and native diffs agree with Git, and the developer console no longer records the route-context error. Update this guide if OpenAI publishes a fixed version or an official recovery procedure.

Step 7: Collect Evidence That Helps the Fix

If the failure persists, capture:

• VS Code version;

• Codex extension version;

• operating system and architecture;

• local, WSL, container, or Remote-SSH environment;

• whether inline Codex review works;

• whether native Source Control and git diff work;

• the first relevant stack line from Developer: Open Webview Developer Tools;

• a minimal repository reproduction with no secrets.

Search the open issues before filing another duplicate. Add a reaction to the matching report and comment only when you have new environment details, a new reproduction, or a verified version outcome.

Common Failure Modes

Why This Recovery Is Trustworthy

Codex writes changes to the repository. Git records the difference between the working tree, index, and commits independently of the Codex Review webview. The inline card and VS Code Source Control are separate rendering paths over the same files.

That separation explains the current reports: the full page can reach a route-context exception while git diff, native Source Control, and sometimes the inline Codex renderer continue to work. Reviewing through those paths preserves the same change evidence without mutating or resetting it.

Verify One External Action After Recovery

Once you have reviewed the repository safely, use a bounded read-only task to confirm Codex can still inspect external evidence. In Codex, paste:

Follow https://aident.ai/SETUP.md

Then ask:

Check my Aident Loadout account and Vault status.
Find one connected read-only GitHub Action that searches issues.
Inspect its current schema, search openai/codex for editor-diff-page, and stop.
Do not edit files or ask me to paste a provider key

Expected result: Codex inspects one live Action schema, returns current matching issues, makes no repository change, and requires no copied provider credential.

Use Aident Loadout to verify one read-only Action. Measure success as one schema-inspected result, zero pasted secrets, and zero local file changes.

Sources

• Codex Diff crashes with "Oops, an error has occurred", OpenAI Codex issue, opened July 24, 2026

• Codex Diff crashes with a non-thread route error, OpenAI Codex issue, opened July 24, 2026

• Codex not showing diff, OpenAI Codex issue, opened July 24, 2026

• Full Review page crashes while inline diff works, OpenAI Codex issue, opened July 25, 2026

• Codex Diff shows "Oops, an error has occurred", OpenAI Codex issue, opened July 26, 2026