get_file tool unable to resolve .aspx.vb or .aspx.cs code-behind if they arent currently open in the Visual Studio editor

[ranasrule]

Select Topic Area

Bug

Copilot Feature Area

Visual Studio 2026 and Visual Studio 2022 with Copilot extension

Body

The get_file tool can only resolve .aspx.vb or .aspx.cs code-behind files in a project if they are currently open in the Visual Studio editor. Closed .aspx.vb files fail to resolve regardless of path format. The only workarounds are to use #file: references or to open the file first as a workaround.

[github-actions[bot]]

💬 Your Product Feedback Has Been Submitted 🎉

Thank you for taking the time to share your insights with us! Your feedback is invaluable as we build a better GitHub experience for all our users.

Here's what you can expect moving forward ⏩

• Your input will be carefully reviewed and cataloged by members of our product teams. 
  • Due to the high volume of submissions, we may not always be able to provide individual responses.
  • Rest assured, your feedback will help chart our course for product improvements.
• Other users may engage with your post, sharing their own perspectives or experiences. 
• GitHub staff may reach out for further clarification or insight. 
  • We may 'Answer' your discussion if there is a current solution, workaround, or roadmap/changelog post related to the feedback.

Where to look to see what's shipping 👀

• Read the Changelog for real-time updates on the latest GitHub features, enhancements, and calls for feedback.
• Explore our Product Roadmap, which details upcoming major releases and initiatives.

What you can do in the meantime 💻

• Upvote and comment on other user feedback Discussions that resonate with you.
• Add more information at any point! Useful details include: use cases, relevant labels, desired outcomes, and any accompanying screenshots.

As a member of the GitHub community, your participation is essential. While we can't promise that every suggestion will be implemented, we want to emphasize that your feedback is instrumental in guiding our decisions and priorities.

Thank you once again for your contribution to making GitHub even better! We're grateful for your ongoing support and collaboration in shaping the future of our platform. ⭐

[ranasrule]

Project type: Web Forms(vb.net)
.NET Framework version: 4.8

update: just discovered that this issue happens in ASK mode and not in AGENT mode

[ranasrule]

ok I think I've figured it out. If the folder the project is in is renamed or moved to a new location this issue starts occurring.