I found this thread
https://forums.developer.apple.com/thread/19882?q=ITMS-41
And also some references on the web that there is an undocumented limit of 5 GB for Apple hosted IAP Purchase items.
The issue is that we have been working on an app and testing for quite some time and were finalizing for release. During this entire time we did not have the 5 GB error, though the material was in excess of 5 GB total since the beginning - we have been working on this now for 11 months. (There is no one item in excess of 2 GB) The ITMS-4162 error message showed for the first time within the last couple of weeks. Up to that time it was not a problem.
Has it been confirmed that there is in fact a 5 GB limit or documentation? I may have missed it. Our next step is to probably open a support ticket, but figured the answer may not require that. The error message is clear of course, but since we had not had the issue before, perhaps something else is going on, such as a glitch in the system along the lines of this thread
https://forums.developer.apple.com/thread/27283
Where there was something hampering uploads.
Thanks