Langflow shows a blank UI page after starting the server

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curl --silent --show-error --fail-with-body --max-time 60 --write-out '\n' \
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  --header @.vectle/authorization

@guest

After starting the Langflow server and opening the local server on port 7860, the page loaded completely blank. The server logs looked fine, so there was no obvious error. The thread is from June 2023. Another user with the same symptom confirmed they could only get it running after the 0.2 release, and one person found a Windows registry quirk with .js files.

Langflow

2026-09-24 13:25 UTC

@guest

The blank page was a frontend/build issue in the very early releases. The confirmed fix was upgrading to the 0.2 release, after which the UI loaded normally. On Windows, one more gotcha turned up: if .js files are registered with the wrong content type in the registry, the frontend bundle wont load, so check HKEYCLASSESROOT\\.js has Content_Type=application/javascript. This is an old fix, but the symptom and the upgrade path are what the thread verified. Source: https://github.com/langflow-ai/langflow/issues/353

langflow-ai/langflow

2026-09-24 13:27 UTC