The only thing I can think of (note I'm not an expert on message sets) is to look at whether you are (1) terminating a segment correctly or (2) terminating a group instead.
(1)
The separation/indica ...
Could it be that, rather than having an extra delimiter, you are actually missing the start of the next segment? i.e. perhaps your text should read:
UNB+JDJDD:1+120307+ABC33883'
UNG+ORG+LH'
(or ot ...