When VidNo fails to render, the cause is almost always one of five common issues. Work through these checks in order — they are listed from most frequent to least frequent.
Check one: GPU drivers and VRAM. Run nvidia-smi in your terminal. If the command fails, your NVIDIA drivers are not installed or not loaded. Install them with sudo apt install nvidia-driver-535 (or the latest version for your card) and reboot. If nvidia-smi works, check the memory usage line. VidNo needs at least 10GB of free VRAM for voice synthesis. Close GPU-intensive applications — games, other AI tools, GPU-accelerated browsers, or CUDA-based programs — and try again.
Check two: disk space. VidNo creates large intermediate files during processing. Run df -h and verify you have at least 50GB free on the drive where ~/vidno/ lives. If space is tight, clear old VidNo cache files with vidno cache-clean, which removes intermediate artifacts from previous processing runs while keeping your final output videos.
Check three: FFmpeg installation. Run ffmpeg -version in your terminal. If FFmpeg is not found, install it with sudo apt install ffmpeg. VidNo requires FFmpeg for frame extraction, audio processing, and final video compositing. A missing or broken FFmpeg installation is the most common cause of rendering failures that occur at the compositing stage (after voice synthesis succeeds).
Check four: Claude API key. Run vidno config --check to verify your API key is valid and has available credits. An expired, revoked, or empty-balance API key causes script generation to fail, which halts the entire pipeline. Log into console.anthropic.com and verify your key is active and has credits.
Check five: recording file integrity. Run ffprobe your-recording.mp4 and verify it reports valid video stream information. Corrupted or truncated recordings — often from OBS crashes or abrupt recording stops — can cause VidNo's frame extraction to fail. Try processing a different recording to isolate whether the issue is with VidNo's installation or the specific file.
If none of these checks resolve the issue, run vidno process your-recording.mp4 --verbose to get detailed pipeline logs. The verbose output shows exactly which stage failed and the specific error message. Common verbose-mode findings include CUDA out of memory (reduce other GPU usage), permission denied on cache directory (fix with chmod), and unsupported codec in recording file (re-export from OBS as MP4/H.264).