The following is a known issue for Magnify:

• Using FORMAT MAGNIFY with TEXT fields that are larger than 32K in size generates a FOCSORT error because the FOCSORT threshold (2GB) is reached.

  As a workaround, the TEXT field must be set as a Binary Large Object (BLOB) field (ACTUAL and USAGE) so that it bypasses the FOCSORT and uses the FOCCACHE instead. This technique writes the content out to disk in chunks as it is processed and is delivered to Magnify as an incoming document.