Another possible problem is that we introduced a new process with python commands.
The MATLAB parser could return a warning in some versions of Matlab:
Warning: Python commands require a supported version of CPython. See Getting Started with Python.
> In panel_process_select>ParseProcessFolder (line 2603)
In panel_process_select (line 30)
In bst_startup (line 396)
In brainstorm (line 205)
In the past, I've seen the code parser crashing on Linux when there were things it didn't like in the code. One thing you could try is to move the file brainstorm3/toolbox/process/functions/process_fooof.m away from the brainstorm3 folder, then restart Matlab and Brainstorm.
Let me know if it solves the problem. In that case, I would need to move all the py. calls outside of the process function...
@Luc FYI