When I try to 'Save Draft' or 'Upload' a manual, I see 'Failed to upload to server.' error message

Please check the following:

　・Whether the size of images or videos registered in the manual exceeds the limit

　　◎Is there an upper limit/restriction on image and video data capacity?
　　https://help.teachme.jp/hc/en-us/articles/900006441863

　・(If you are using an Android device)
　　Try reducing the resolution of the video before registering it to Teachme Biz

　・Check if the title or description contains emojis/device-dependent characters/special characters
　　(If they contain emojis/device-dependent characters/special characters, please remove them)

　・Try saving or uploading images and videos one by one as a workaround