Your model is already log-lineraised, it is about the way you treat your data. It is not possible to just insert data that you download from some site. It has to match model variables. As an example, in your model output is given as percentage deviations from steady state of output per person, ie a stationary data series, but the data you (most likely) took is overall output which is non-stationary. Thus, you have to treat the data to match your variable.
Read the file and look around the forum, there are plenty of posts about exactly just that 