Before revision:  We also discuss how these errors affect the very similar Friston (2014, URL and, where appropriate, mention consequences for the newer proposals in Friston (2019, arXiv:1906.10184v1 ) and Parr et al. (2019, URL The errors call into question the purported interpretation that the internal coordinates of every system with a Markov blanketwill appear to engage in Bayesian inference. In particular, in addition to highlighting the implicit restriction to linear models, we identify three formal errors in the main argument of Friston (2013): The first concerns the rewriting of the  equations of motion of systems with Markov blankets which turns out not to be generally correct .
After revision:  We also discuss how these errors affect the very similar Friston (2014, URL and, where appropriate, mention consequences for and reveal, up to now unacknowledged, differences to newer formulations of the free energy principle. In particular, we reveal that various definitions of the equations of motion of systems with Markov blankets which turns out not to be generally correct .