In most situations you should check the clear faults box. All the devices that are supported by this software were done at different times. Some of them do not comply with the PMBUS way of identifying a device. PMBUS standards says that IC device ID is the way to identify a device. It's a command and it returns the name of the device and it's a read only command. Some older devices used the MFD ID or MFR model. As the software may have multiple of these devices connected at the same time, and if a command is not supported you might get a fault. For that reason this checkbox is included, to clear the fault at the beginning when you start the GUI. During any subsequent uses of the GUI if a fault happens it will show up.