User skill can not be loaded on Windows

[aeschli]

In Windows, the read_file tool still refused to read the skills at user folder.
It worked in MacOS.

OS: Windows 11
Copilot Chat: 0.36.2025121103
VS Code: 1.108.0-insider

User
<environment_info>
The user's current OS is: Windows
</environment_info>
<workspace_info>
There is no workspace currently open.
</workspace_info>


[copilot_cache_control: { type: 'ephemeral' }]
User
<toolReferences>
The user attached the following tools to this message. The userRequest may refer to them using the tool name with "#". These tools are likely relevant to the user's query:
- read_file
</toolReferences>
<context>
The current date is December 12, 2025.
Terminals:
Terminal: pwsh

</context>
<reminderInstructions>
When using the replace_string_in_file tool, include 3-5 lines of unchanged code before and after the string you want to replace, to make it unambiguous which part of the file should be edited.

</reminderInstructions>
<user_query>
use 'read_file' to read the skill-creator skill.md
</user_query>

[copilot_cache_control: { type: 'ephemeral' }]

Assistant

🛠️ read_file (call_96060706) {
  "filePath": "c:\\Users\\username\\.claude\\skills\\skill-creator\\SKILL.md"
}

Tool
🛠️ call_96060706
ERROR while calling tool: File c:\Users\username\.claude\skills\skill-creator\SKILL.md is outside of the workspace, and not open in an editor, and can't be read
Please check your input and try again.

[copilot_cache_control: { type: 'ephemeral' }]

Response
Assistant
I'm unable to read the file `c:\Users\username\.claude\skills\skill-creator\SKILL.md` because it's located outside the current workspace and not open in an editor. If you can open the file in your editor or provide its contents, I can help with it.

Originally posted by @ming86 in #280690

[aeschli]

0.35 release PR: microsoft/vscode-copilot-chat#2564
main PR: microsoft/vscode-copilot-chat#2563