FDCAN FIFO full

[ChaitanyaParate]

I am using a custom PCB with stm32g474 and I am trying to get the CAN peripheral working. I believe I have everything set up correctly (bit rate, RAM etc) but when I call HAL_FDCAN_AddMessageToTxFifoQ(), FIFO is full error is raised after 3 iterations.

Any help is appreciated.

[MHoll.2]

Can You confirm that You have a working CAN-bus (2x120R Termination, and at least 1 other node that is working, for example a CANBus dongle)?

Why do You use a isolated CANBus driver when You use the same ground (and 5V) on both side of the isolation?