Not sure if you solved this already, but you need a prior with positive support. A well-behaving one for training is the log Normal prior. Also see A toy normal model failed (klqp) and why? for some discussion of priors.
Not sure if you solved this already, but you need a prior with positive support. A well-behaving one for training is the log Normal prior. Also see A toy normal model failed (klqp) and why? for some discussion of priors.