I had old version 6.1.3.2. Did just try to upgrade to 6.4.0.3 (on Windows). Same issue after upgrade.
I also have same error on Unbuntu, not sure what version of LibreOffice I use there yet.
This is the word field code:
{SECTIONPAGES \* Arabic \* MERGEFORMAT}
Looks like the result allways is "2".