We’re sorry for the error you’ve experienced when posting your video to VSCO.
First, please update your VSCO app and your operating system to the latest versions and try posting the video to VSCO again.
If this doesn't help, below are the requirements for a video to successfully post to VSCO.
1. Your video can be no smaller than 360 x 360px and no larger than 1080p
2. The file size of the video must be between 1kb and 1gb.
3. Length of the video can be no longer than 1 minute.