Siemens S7-400 SFB4 Question

I have modified an existing program on an S7-400 and download just the FC that had the change made to it while the PLC continued in RUN mode.

The problem I have is that the instance of SFB4 (TON) that I used is not running when IN gets a positive edge. When downloading SFB's is it necessary to restart the PLC?

Thanks.

The SFBs are already loaded into the processor.

If you added an SFB instruction, it should have generated a datablock. Did you download the datablock too?

No I didn't I completely forgot about that. Thanks Tim now I feel like an ***