GitHub Copilot fails on virtual member files (document not found in workspace / ignored document)

[VMURAZ20]

Summary

When opening virtual members from IBM i (or using custom scheme extensions like Arcad Skipper/Code for IBM i VFS), GitHub Copilot (and other inline completion providers) ignores the open documents and fails to generate suggestions.

Context / Trace Logs

Inspection of the GitHub Copilot Output logs (GitHub Copilot channel in VS Code) reveals the following trace when working on a member:

2026-09-17 10:00:22.335 [trace] [NES][Triggerer][onDidChangeTextDocument] Return: ignored document
2026-09-17 10:00:22.346 [trace] [NES][Provider][provideInlineCompletionItems][0e5c] Return: document not found in workspace

Did anyone experience the same issue?

Will some correction allow to solve this ? 

Thanks a lot

[SanjulaGanepola]

This has been mentioned in a few different issues before:

• GitHub CoPilot Inline Suggestions Bug #3356
• Copilot ghost text (inline suggestions) does not work for source members opened via the "member:" scheme #3444

From what I've seen in the previous issues, Copilot seems to work sometimes on source members, but then randomly stops working. This would be a bug in Copilot and cannot be resolved in Code4i