Thank you Dan for your reply, I did exactly what you recommended, still have the below error:
C:\Users\zahransa\anaconda3\python.exe C:/Users/zahransa/PycharmProjects/opm/plot_opm_data.py
Opening raw data file C:\Users\zahransa\mne_data\MNE-OPM-data\MEG\OPM\OPM_SEF_raw.fif...
Isotrak not found
Range : 0 ... 700999 = 0.000 ... 700.999 secs
Ready.
Current compensation grade : 0
Reading 0 ... 700999 = 0.000 ... 700.999 secs...
Filtering raw data in 1 contiguous segment
Setting up low-pass filter at 90 Hz
What you're showing is the output of the plot_opm_data.py example script. What I suggested was to re-install MNE-Python and its dependencies and examine the output of *the reinstallation process*, not the output of the example script. Did you do that? What (if any) errors did you see during reinstallation? How did you do the reinstallation (pip, conda, something else)? Did you search for problems related to matplotlib and ft2font? What does mne.sys_info() tell you?
-- dan
Daniel McCloy https://dan.mccloy.info
Research Scientist
Institute for Learning and Brain Sciences
University of Washington