In LibO Calc 3.3 it was possible to name a cluster of cells, say C2:E5, and use it as a reference in a formula. E.g., if C2:E5 is named "Totals", this reference can be used in =SUM(Totals) instead of SUM(C2:E5).
In LibO 3.4.2 this feature does not work anymore. It returns an error with "#NAME?"
3.4.2 is supposed to be a functional stable version. This is bad and will turn off many people.
Sure that you don't mix it with database ranges which does not work in 3.4.2 but should work again in 3.4.3?
You'll find named ranges at Insert->Names->Define whereas database ranges are at Data->Define Range.
*** This bug has been marked as a duplicate of bug 39333 ***