Hi Phillipe.
"Large Object Support" is reserved for *very* long reports - where the number of pages is extremely large, (over 1000 pages).
Large Object Support breaks the report into 100-page chunks, so that the ENTIRE report doesn't need to be transmitted to a client in order for it to be viewed. This saves processing time, and network bandwidth. It was especially important 10 to 15 years ago, when network infrastructure inside companies was very slow (anywhere from 5 to 20 Megabits) and external network infrastructure was usually dial-up modems.
If the document you are trying to load is not a line-data or AFP report, you shouldn't be using Large Object Support.
I strongly suspect you don't have the correct document type configured in your Application setting.
Give us some more information (type of document, formatting, style, or maybe the Application definition) so we can try to help out a little more.