Parsed word not recognized (UNK)

Question

I am getting an unknown word (UNK) with an approved parse. Please help me understand why:

Answer 1

It is likely that in the source FLEx project, the word has not been analyzed, or not been approved. 

The help file has a good troubleshooting section for such messages:
https://software.sil.org/downloads/r/flextrans/resources/UserDoc.htm#sTroubleshooting

Answer 2

It could have been that the changes you made to your interlinear text were not saved to disk by the time FLExTrans' Live Rule Tester read the text. After a text change a fairly reliable procedure to save it to disk is to switch to the Lists area of FLEx and switch back.