TagNullPointerException when going back through Tabgroup activities

A little elaboration. There are Activity A, B and C You start A with Id “A” then you start B with Id “B” then you start C with Id “C” and from C you again start another instance of B with id “B” (it may happen, because B may be a ResultListScreen which may called for several time with Load More type button) The problem is that in ArrayList idList...