I am the IT admin of a single provider office with about 7 (8 including the main computer). I am fairly knowledgeable about computer networking/jargon. Our office for at least the past year has had this issue pop up- usually at least twice a day.
sometimes our staff when booking appts, printing practice documents or other daily tasks; Amazing charts crashes saying Error: (91) Object variable or With block variable not set.

I suspect that this is caused by the main computer not sending something fast enough but the computers that have this issue the most are all wired. Iam just interested in knowing if other offices have this same issue or a mistake I've made somewhere.
If it helps all computers are running AC 9.3.1 and use Win 10 pro.

can provide more details upon request.