Sidebar icons render as empty placeholder rectangles after recent update (macOS)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

After updating Claude Code, the icons in the left-hand sidebar render as empty placeholder rectangles instead of the actual icons. The icons next to "New session", "Routines", "Customize", "More", and the top tabs ("Chat", "Cowork", "Code") all appear as blank squares with just the rectangle outline. The username avatar at the bottom is also affected.

Text labels render correctly — only the icon glyphs are missing, which suggests an icon font asset is failing to load.

Steps to reproduce
Update Claude Code to [version]
Launch the desktop app on macOS
Observe the left sidebar
Expected behavior
Sidebar items show their normal icons (new session, routines, customize, etc.).

Actual behavior
All sidebar and tab icons render as empty rectangles. See screenshot.

<img width="528" height="424" alt="Image" src="https://github.com/user-attachments/assets/3a550e02-997b-485c-8276-24326c46b0b9" />

Environment
Claude Code version: 2.1.150
Install method: [desktop app / npm / homebrew]
OS: macOS, Darwin 25.4.0
Last known working version: previous
Troubleshooting already attempted

• Quit and relaunched the app
• Cleared caches: rm -rf ~/.claude/cache ~/Library/Caches/com.anthropic.claude

Additional notes
I've seen mentions of similar reports elsewhere, so this may affect more than one user on the current release.

Hypotheses:

From ~/Library/Logs/Claude/unknown-window.log, first and only occurrence at app launch in 2.1.150:

2026-05-23 14:22:36 [error] Setting the document's base URI to 'https://claude.ai/' violates the following Content Security Policy directive: "base-uri 'none'". The action has been blocked.

This appears to be the root cause: the renderer tries to set <base href="https://claude.ai/">, the CSP base-uri 'none' directive blocks it, and relative asset URLs (icon SVGs/fonts) then fail to resolve — leaving the bounding boxes visible but the icons themselves blank.

No font 404s or asset-load failures in main.log or swift.log. The CSP block happens before any asset request is even attempted.

What Should Happen?

Sidebar items and top tabs should show their normal icons (new session, routines, customize, chat, cowork, code, etc.), as they did before the update.

Error Messages/Logs

From ~/Library/Logs/Claude/unknown-window.log, first and only occurrence at app launch in 2.1.150:


2026-05-23 14:22:36 [error] Setting the document's base URI to 'https://claude.ai/' violates the following Content Security Policy directive: "base-uri 'none'". The action has been blocked.

Steps to Reproduce

1. Update Claude Code to [version]
2. Launch the desktop app on macOS
3. Observe the left sidebar and top tabs

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.150

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_