I've tried uploading again, this time using a 55MB video. not a single UBB.threads software issue. I attempted to upload with both drag-and-drop (DropZone), and using the file-picker. See attached screenshots.
If you are uploading any type of file, you should probably wait until it completes and is listed in the Attachment Manager before progressing away from it.
If you are uploading a large file on your network utilizing QoS, the upload may be stalled so "more important" traffic can be transferred.
