The sample firmware “hub_msd (HarmonyFramework\usb\apps\host\hub_msd)” works well on PIC32MX270F256B-50I/SP.
However, the following modifications are needed in drv_usb_external_dependencies.h.
//#if defined DRV_USBHS_INSTANCES_NUMBER <------------..
//#if defined DRV_USBHS_INSTANCES_NUMBER <------------..