"Application Error" upon selecting the "Install in Insiders" link

### Describe the bug

1. I visit https://github.com/github/github-mcp-server .
2. I find the friendly green **Install server** link.
3. I select it.
4. A new tab opens with this message

### Affected version

I can't even install it.

### Steps to reproduce the behavior

See description.

### Expected vs actual behavior

The server is installed.

### Logs

No logs provided.