meet the problem via rendering with fumefx

It always prompt the mistaking note,and i can’t render,i just follow the example of krakatoa document on the website,please tell me how to resolve ?thanks a lot .please check the image for this issue.

The error message is NOT for this flow! It is for modifier KCM_Density where the Output is not connected to anything according to the message.
If you do have a KCM_Density modifier on the stack, make sure it is correct or disable it. Note that the error messages in the MagmaFlow Editor reflect the whole modifier stack, not just the current modifier. When the current modifier has an error, the message will say so (“ERROR in Current Flow…”). When the error is in another modifier on the stack, the name and ID of the modifier will be listed.

Hope this helps!