We were passing bKohaColumnsUseNames and loaded_from_state to DT's constructor, which are custom properties. With the upgrade to DataTables 2 this behaviour is no longer working. Custom properties cannot be retrieved using DT's api.
Moved to Bug 38436: Store loaded_from_state in data instead of DT's settings Bug 38436: Store bKohaColumnsUseNames in data instead of DT's settings I didn't manage to provide an isolated patch. *** This bug has been marked as a duplicate of bug 38436 ***