When streaming is true you're just requesting the entire file up front which shouldn't be a problem for any servers but it is a problem for WebViewer if the file is large because it will need to be completely downloaded and parsed at the start which is slow.
When streaming is false WebViewer is just requesting the parts of the file it needs and this usually isn't a problem for most web servers but there can be issues if you're fetching things in other ways and not respecting the range headers.
Your error message says 416 which means "Requested range not satisfiable". The part at the of the url "&_=4294967295,8589934590
" is added by WebViewer to help with caching issues and represents the range that it is requesting. These numbers seem a bit strange to me because they're very large. 4294967295 is 2^32 - 1 so maybe there is some sort of integer weirdness/overflow going on since your file is definitely not 4GB.
Are you able to reproduce the issue with an uncustomized WebViewer? Do you see the issue when running the WebViewer samples on your server? If you can then can you send me the XOD file so we can investigate.
PDFTron Systems Inc.