Error: Cannot read file – File > Open – UI freeze on large datasets

Goal

Determine how Blender’s File > Open operation handles large .blend files and why the UI becomes unresponsive without a progress indicator.

Constraints & Uncertainty

• Large files (>200 MB) cause the interface to freeze during loading.
• No progress bar or cancel option is shown, unlike the console error “Error: Cannot read file” that appears only for corrupted or missing files.
• Current releases up to 3.5 lack a UI feedback mechanism for import duration.

Unresolved Questions

1. Should Blender implement a progress bar or loading spinner for File > Open when handling large datasets?
2. What trade‑offs exist between a blocking UI during import and an asynchronous loading approach?
3. How can the error handling be unified so that users receive consistent feedback for both corrupted files and long‑running imports?