[Post processing question, am I doing this right?]

What does the M0 command represent? My printer is a crs10 pro, I just flashed it with tiny machines version of Marlin's firmware. I'm not sure is the problem originates with my firmware or just my knowledge of Cura. Where can I read about different options?

[Post processing question, am I doing this right?]

I've begun to explore some of the more advanced features in Cura with post processing but have ran into an issue. 

 

I want to learn how to add a pause at a specific layer height, however when I do my printer's firmware (tiny machines) thinks I have run out of filament and prompts me to click yes/no. Yes does nothing even after a very long time and no aborts the print. I've added a few pictures if I didn't described it very well. 

 

Did I fill out the post processing options correctly or do I need to do something differently to pause at layer 9 and then successfully resume my print? BTW I'm also using the newest version of Cura 4.8 I think it is now.