BFL and ComfyUI roll out fixes for FLUX 3 Klein launch issues
FLUX 3 Klein's launch day was marred by poor image quality, anatomical errors, and broken ComfyUI workflows. Black Forest Labs (BFL) and the ComfyUI team have since rolled out multiple rounds of fixes — updated weights and workflows are now available, and affected users are encouraged to re-download.
Confirmed
- BFL uploaded new variant files for FLUX 3 Klein on Hugging Face. According to the Rebel AI account, these resolve the image-quality issues seen on launch day, and the post included sample images urging users to re-download (m1).
- ComfyUI shipped v0.41.2 (workflow fixes) and v0.41.3 (updated workflow plus a dedicated prompt upsampler); official weights and workflow files are hosted in the black-forest-labs/flux-3-image repo on Hugging Face (m2, m3).
- Alexis from the ComfyUI team acknowledged that the launch-day example workflow was poorly configured, causing many users to hit anatomical errors or subpar results. It was rebuilt in collaboration with BFL and released in v0.41.3; the new example enables the prompt upsampler and doubles the number of steps (m5).
- The prompt upsampler must be downloaded separately and weighs in at 9.75GB (m3).
Unconfirmed
- The technical details of the fixes mostly point to external posts and GitHub discussions that aren't elaborated on in the source material, so a full changelog can't be verified.
Why it matters
- Tracing the fix timeline, Reddit user @Mad4reds noted that BFL initially only responded on GitHub while the official ComfyUI blog stayed silent, and the lack of communication frustrated the community. This incident highlights how important ecosystem tooling support and transparent communication are after a high-profile model release.
2026-10-18 ~ 2026-10-19 · 5 related posts
- Episode 1: Black Forest Labs Open-Sources FLUX.3 Image Klein: 5.6B Model Runs 4K Generation on a Single Consumer GPU(2026-10-14, 35 posts)
- Episode 2: Black Forest Labs Open-Sources FLUX.3 Image Klein, Ecosystem Rushes to Support It(2026-10-15, 7 posts)
- Episode 3: BFL Updates FLUX 3 Klein ComfyUI Workflows and Shares New Samples(2026-10-16, 4 posts)
- Episode 4: Flux 3 Klein open-sourced: text-to-image panned, high-res editing shines(2026-10-16, 18 posts)
- Episode 5: ComfyUI v0.41.0 Adds Day-One FLUX.3 Image Support(2026-10-16, 3 posts)
- Episode 6: Quantization Benchmarks Show FLUX 3 Klein Running Over 2x Faster with Better Quality(2026-10-17, 3 posts)
- Episode 7: BFL and ComfyUI roll out fixes for FLUX 3 Klein launch issues(2026-10-18, 5 posts)
Primary sources
- Flux 3 Klein Gets Updated ComfyUI Support Following Community Criticism — ganrocks007 · 2026-10-18
- [source] ComfyUI v0.41.3 fixes FLUX 3 Klein launch workflows: prompt upsampler on, 50 steps — Lexius2129 · 2026-10-18
- [source] BFL uploads new FLUX 3 Klein variants fixing day-one release issues — Star-Light-9698 · 2026-10-18
- [source] ComfyUI v0.41.3 fixes Flux 3 Klein workflows, adds 9.75GB Qwen3.5-9B prompt upsampler — Mad4reds · 2026-10-19
1 near-duplicate retellings: Mad4reds