I think that your FMU was wrapped as a Model Exchange FMU (version 2.0) but you are trying to run it as a Co-Simulation FMU. This is I believe the reason why PyFMI PyFMi is showing the following error pyfmi.fmi.FMUModelME2' pyfmi.fmi.FMUModelME' object has no attribute do_step. The do_step () method is only available in Co-Simulation FMU. If you really wanted a Model Exchange FMU, then you should use the Model Exchange functions to drive your FMU.