On the bottom of the Aquarite there should be a grey "phone cord" coming out of the box. It's possible someone stepped on that cord and pulled it out. The cord goes from the Aquarite box to a PVC fitting in your return line.
1) if grey phone cord is plugged in, inspect entire length of cord to see if there are any cuts/nicks in it. Landscaper may have hit it with a weedwacker.
2) if grey phone cored is NOT plugged in. Find cord on ground, (Hopefully the phone plug end with still be on it) and plug it in.
Does the no flow light eventually go out, leaving no LED lights lit? No "Power" "Generating" "Super Chlorinating" lights lit? Are there any # in the display? It's possible the black board thermistor may have failed. It can be replaced. Some pool companies will tell you it is necessary to replace the PCB board. Not the case.