I deployed OVA of LTS2015 version. Trying to change I10nsubjects vocabulary, I removed all default subjects and added some new ones on the top level. The problem is that I cannot add second level items - the list of possible parents is blank (see screenshots). There were old items in this list (before I deleted them), but never the new ones I've just added. The same problem exists in I10ncoverage vocabulary, but I have no problem with the old topic/subtopic vocabularies. Is there any additional config needed or it's just a bug?