Both myself and WD9DUI have had multiple instances of VarAC becoming "unresponsive" or simply crashing (and leaving Vara-HF running) over the past couple of weeks. This happens during a QSO, but not while the program is idle.
We've had this happen while in QSO with different stations.
We both are running the latest VarAC and VARA-HF (VarAC 3.0.2, Vara-HF 4.5.5). and have no (or in my case ONE other program running (Log4OM).
We both are running robust computers, with plentiful RAM (in my case 16 GIG).
We've both set VarAC to run in "real time" in Windows 10.