There are at the moment a number of long-standing discrepancies between observables in b->c semileptonic decays and their Standard Model predictions. In addition there is the long-standing tension between inclusive and exclusive determinations of Vcb, the latter being obtained from these same decays. Here I will discuss the state-of-the-art lattice simulations addressing these issues. After reviewing the status of B->D(*) form factors I will discuss in more detail new results from HPQCD that treat the ‘b’ quark fully relativistically.