[Bug] Claude lost ability to analyze video files
Bug description
Since approximately September 16, 2026, Claude can no longer process or analyze video files (.mp4). When a video file is uploaded, it returns a "binary file" error instead of analyzing the content (frames, actions, audio context).
Steps to reproduce
- Upload a .mp4 screen recording to a Claude session
- Ask Claude to describe what happens in the video
- Claude fails with: "This tool cannot read binary files. The file appears to be a binary .mp4 file."
Expected behavior
Before ~September 16, Claude could analyze video files — extracting frames, describing visual content, identifying on-screen elements, and summarizing what happens in the recording.
Actual behavior
Claude returns a binary file error and cannot process the video at all. The capability is completely lost, not degraded.
Environment
- Claude Code version: latest (as of Sep 25, 2026)
- Models affected: claude-opus-4-6
- OS: Debian 12 (Bookworm), also tested on Android mobile
- Platform: claude.ai + Claude Code CLI
- File format tested: .mp4 (screen recording)
Additional context
This regression began around September 16, 2026. Before that date, video analysis worked reliably across sessions. The loss appears to be related to the same infrastructure change that caused regressions in reasoning, verification, and response completeness across all model tiers.