When converting very large documents, you may experience a problem with running out of memory.
This is generally a memory limitation imposed by the Operating System since memory allocation fails at about 1 gigabyte.
In order to ensure our software can remain compatible with older systems, PDF2XL is a 32-bit program, though it will run on a 64-bit system.
The Workaround
To successfully convert the document, it will be necessary to convert it in sections by using page ranges and converting to the existing sheet.