Arduino PixyCam2: No Serial Communication

I have a PixyCam2 that just yesterday was working perfectly. I wanted to make some improvements. I got a new computer in the month or so since I last modified it, so I had to download the library and Arduino IDE again. I started writing some code for the PixyCam and I uploaded to find that (no surprise) it didn't work. So I threw in some Serial.println() statements because of the IDE's disappointing lack of breakpoints.

I did all the sanity check steps: make sure the monitor is the same baud as the arduino, do Serial.begin(115200), et cetera, and it still wouldn't print. I tried the hello world program in the library and it said:

error no resposne

The only variable I can think of changing between programs is my computer... is there anything you think could cause this issue, and how would I fix it?

because of the IDE's disappointing lack of breakpoints.

Breakpoints are actually pretty useless when debugging embedded software like this.

Can you post your code and wiring schematic?