Problems with Multinest and omega_b, even if omega_b is not sampled (?????)

[arthurmloureiro]

Hi!

It seems like every time I try to sample any likelihood with Multinest, I encounter the following issue:

=>thermodynamics_helium_from_bbn(L:655) :condition (omega_b < omegab[0]) is true; You have asked for an unrealistic small value omega_b = 4.046829e-04. The corresponding value of the primordial
 helium fraction cannot be found in the interpolation table. If you really want this value, you should fix YHe to a given value rather than to BBN

This error occurs even when I am not sampling omega_b.

If I try to sample the PanthonPlus likelihood with omega_b fixed using Multinest, this problem appears.
If I try to run any likelihood related to planck (lite or full) with Multinest, the code breaks because of this issue.

Does anyone know how to get a minimal planck example running with Multinest in Monte Python?

[arthurmloureiro]

Another related issue is that changing samples seem to give different results.

Here's a panthon+ test with Multinest (blue) and Metropolis Hastings (red):