They are very old webinars, from very old versions of STKO where we didn't have adaptive time step.
model_3d_basic.scd
We used a fake AnalysisCommand to set up the basic ingredients of the analysis, but we set the duration and number of increments to 0.
Then we put a custom Tcl command (named RUN in this file) that performs adaptive time step analysis with a total duration of 1 second, and initial number of increments = 2000 (as you can see from lines 6 and 7 of the Tcl script).
In the newer versions we do have built-in adaptive time step in the AnalysisCommand, so there is no need for the custom Tcl script after the analysis.
This is how the file should be now (note that you should run it with openseesmp, it's parallelized using 8 partitions):
Try the same change also in the other files