I have made sure the \+it ...\it* reference letters have been moved to outside the \xt into an \xta tag
and I have made sure that any reference to an alternative ref location (using the "|") have been preceded by \xt (even if the previous references are in an \xt
but, it still fails.
Is it possible that the \+it ...\+it* letters in the \xo and \fr markers could be causing the problem?
e.g.
x - \xo 1:1\+it m-r\+it* \xt Vgl EstGr 2:19-23\x*
and
\f + \fr 8:12\+it p\+it* \fk Judeërs: \ft Vgl voetnoot by \+xt EstGr 8:3\+xt*.\f*