[BUG] Desktop app split-view pane renders black/blank for a specific session

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report
• [x] I am using the latest version of Claude Code

What's Wrong?

Using Cmd/Ctrl+click on a claude.ai/code/session_... link inside a chat in the Claude Code desktop app opens a split pane as expected, but the pane's content never renders — it stays solid black indefinitely.

The same session opens and renders correctly when the link is opened directly in a regular browser tab (bypassing the desktop app entirely), so the session data itself is not the problem — this looks specific to the desktop app's split-pane rendering.

What Should Happen?

The split pane should render the linked session's content, matching what the browser shows for the same session.

Steps to Reproduce

1. In the Claude Code desktop app, open a chat containing a link to a large/older session (one created via web claude.ai, with high context usage).
2. Cmd/Ctrl+click the session link to open split view.
3. A pane opens but never renders content — solid black screen, indefinitely.

Workaround: opening the same session URL in a normal browser tab works reliably.

Claude Code Version

Not confirmed by the reporter (desktop app version not captured at time of report). Container/CC version observed elsewhere in the account around this time: ~2.1.267–2.1.268.

Operating System

Not explicitly confirmed (desktop app, platform not specified as Mac vs Windows by the reporter).

Additional Information

• Affected session: session_018np192ewqAn64RHgmV4BgT (origin: web_claude_ai — created via the web claude.ai UI, not the desktop app itself)
• Session context usage at time of failure: ~670,000 tokens (large transcript)