Identify whether the upload failed before transfer, during transfer or while validating the file. Check the visible error, actual size, duration, picture, audio and available storage before retrying. A full progress bar means bytes were sent; the episode becomes ready only after validation and storage succeed.
Identify the stage and keep the source safe
Note whether the problem appears during file selection, transfer or validation. Keep the original recording on your device and record the visible error wording and approximate time. Check the episode library before another attempt so you know whether a ready episode was created. Avoid several simultaneous attempts: they make storage and status harder to understand. An unfinished attempt is not evidence that a playable episode or successful clip exists.
Verify the actual file rather than its filename
Play the source locally at the beginning, middle and end. CastCuts accepts MP4, MOV and WebM with both video and audio; an audio-only file, silent screen capture without an audio track or incomplete container can fail validation. Check the actual size and duration against the current limits, normally 512 MiB and two hours. A supported extension does not guarantee compatible contents, and renaming one does not repair them. Prepare an external compatibility export when the source is readable but unsuitable, preserving the master for comparison.
Check interruptions, sign-in and available storage
Keep the upload page open while sending the file; leaving it aborts an active transfer. Check that the device remains connected and that your session is signed in. Review the library or storage view for existing episodes, clips and pending work before retrying a quota error. Delete only files you have already saved and no longer need. Cleanup may take time, so do not assume a deletion request instantly frees every reserved byte. The current upload workflow does not resume from an interrupted offset; a deliberate retry starts a new transfer.
Change one cause and verify the next result
Address the specific cause before retrying: compatibility, connection or storage. Wait for a ready episode and preview its actual picture and sound before making a test clip. If the failure persists, contact support with its stage, time, browser and non-sensitive format, size and duration details. Keep private recordings out of public reports. Preserve your source and download finished work before expiry.
Fictional worked example: a full progress bar followed by rejection
Illustrative example. The people, recordings and results described here are fictional.
A creator sends interview.mp4, reaches full upload progress and receives a validation error. Local playback reveals picture without an audio track; sound was exported separately. They prepare one complete video with the intended mix instead of repeating the same upload. The corrected episode reaches ready state and a downloaded test confirms both voices.
Match the fix to the failure stage; completing the transfer is only one part of upload success.
Check before you finish
- The failure stage and visible error have been recorded without exposing private content.
- The actual file plays and contains valid video plus audio within the limits.
- Connection, signed-in session and available storage have been checked.
- The corrected attempt reaches ready state and passes a real preview.
Practical questions
Why did upload progress finish if the episode failed?
Transfer and validation are separate stages. The server still checks the completed video's contents and stores it before a ready episode appears; a full progress indicator alone does not confirm acceptance.
Can I resume an interrupted upload?
The current workflow has no resumable upload. Keep your source, check the library and available storage, correct the interruption and start a new attempt deliberately.
Will renaming the file to MP4 solve validation?
No. The video must actually contain a readable supported container, picture and audio. Use a proper export or conversion when needed and play the resulting file before retrying.
Use this workflow in CastCuts
Prepare a compatible source for clipping
CastCuts selects continuous 1–90 second excerpts and exports 9:16, 720 × 1280 H.264/AAC MP4 files. Automatic transcription and transcript-based suggestions support English and require review. Free exports include CastCuts branding; Pro removes it from new renders for $9 USD/month, with the same processing and storage limits. Episode media is retained for 24 hours. Keep your originals and download finished clips before expiry. Publishing is manual.