No device scan while a radio is open. Opening the Source section, or pressing Refresh, looked for hardware even while a radio was streaming, and the RTL-SDR driver's probe opens and resets every dongle it finds, including the one in use. On an RTL-SDR user's machine the next rate change after such a scan faulted inside the USB library. The scan now waits until the radio is closed, and the Source section says so.
A radio the driver faulted under is reopened once. When a driver fault is caught inside FoxSDR, the radio used to stay dead until the program was restarted. It is now reopened once, automatically, at the same rate, frequency and gain, and started again if it was running; the log says whether that worked. If it did not, the old message stands.
SHA-256 of foxsdr-setup-0.90.1.exe:
fa060e528100fef60e4f6b8729b461d2c28a4f8d5e80f94c27b7fadeeaf96fb6