The code generated for an F303CCTx LL Active level Inversion of USART1 RX is :-
which doesn't compile. Where as I think it should be :-
The TX doesn't have this problem.
I also found that I need to add :-
/* Enable RXNE and Error interrupts */
to enable the interrupts I need. As it would seem the best place to add these is in the MX_USART1_UART_Init function that is generated, would it be possible to add a user code section at the end of the function to add this code to.