System Workbench for STM32

to have cdc revceive_fs you must kick of reception , it will then be called in isr by usb stack when data will come from host, You start the rx by calling

uint8_t USBD_CDC_ReceivePacket(USBD_HandleTypeDef *pdev)

note that many hal driver and f/w will fail with freertos mainly because of usage hal_tick for time out or delay.

systick isr priority is