If you can’t upload videos to Prezi, first check your file format and size—Prezi typically supports MP4 (H.264 video codec with AAC audio), and large files may fail during upload.
Make sure your internet connection is stable and try uploading from the latest version of Chrome, Edge, or Safari after clearing cache or disabling browser extensions.
If the upload still fails, compress the video, reduce resolution (for example to 1080p), or re-encode it to standard MP4 using a converter before trying again.
You can also upload the video to YouTube or Vimeo and embed the link in Prezi instead, or contact Prezi Support if the error persists with a specific message.
If support does not reply, you might want to consider posting a complaint on Xolvie in order to bring attention to the issue and try to find a solution.
