I have to quit my client after every match to clear out my ram. If I don't my Mac will automatically start closing excess windows to conserve ram, and I'll frequently get the message "Your system has run out of memory, please close programs to free up space". This is the only program I've ever used that has caused this problem. If I don't clear my ram in time, or shut down the program quickly enough I'm forced to force restart my computer out of it completely freezing. I really enjoy PTCGO, but this RAM issue is killer for me. I'm on a 2015 13" Macbook Pro, running High Sierra 10.13.2, with 8GB of Ram, an i5 processor, and over 30GB of Hard drive space available.