Tracker-Ticket for all schema and solrconfig issues surfaced after LTS release:
modifiedby is multivalued but was not before and has no reason to be: java.lang.IllegalArgumentException: cannot change DocValues type from SORTED to SORTED_SET for field "modifiedby"
multiple values encountered for non multiValued field mods.dateIssued.host: [2011-07-05, 2011-05-16, 2011-05-09, 2011-05-23, 2011-06-28, 2011-05-31, 2011-06-07]
multiple values encountered for non multiValued field mods.part.: [Wintersemester 2016/2017, Wintersemester 2016/17, Nr. 5]
content of pdf was not indexed
worldreadable* fields are missing