I tried out the explicit solution MCMC option (which used to work fine, if slowly), but it does not seem to converge anymore for the Lotka-Volterra example. Probably we've introduced a bug somewhere, I will try to figure this out when I have time.
I fixed a bug due to the mean shift, which was not being taken into account in calculating the likelihood for the explicit solution. I'm reasonably confident that this resolves the issue.
I tried out the explicit solution MCMC option (which used to work fine, if slowly), but it does not seem to converge anymore for the Lotka-Volterra example. Probably we've introduced a bug somewhere, I will try to figure this out when I have time.