Ted here from Shopify, thanks for posting your query!
Great question! When this error occurs, it normally means the system is unable to read the ID. Could you make sure the ID:
Other than this, there may be an issue with the device or the browser you are using to upload these documents. Please update the browser and clear its cache as mentioned here. Using a different device or browser can help as well.
Please let me know how this goes! Our live chat, email and callback advisors are also available here 24/7 if you would prefer a faster response. Just click Support > Contact Support in the main menu or our Facebook and Twitter support is also available.