I'm new to KSP, albeit I think I got the basics of... things. Anyway, people keep saying KER is a must-have, so I gave it a go. And, sure enough, it has plenty of info during the building stage in KSP. However, when I'm actually in-flight (or even stationary at the launch pad), the KER button is darker and seems to be not available.
It would be a massive help to know the remaining dV I have. Thus far I need to eyeball it, which is usually OK (I tend to over-engineer a bit anyway), but on a few occasions where I messed up a planned manoeuvrer I could REALLY use this... Does KER not have this information? Or am I just not accessing this info correctly?
EDIT: Dear administrator - I've figured it out. KER has a setting where I either need to put in an additional module on my rocket, or toggle the setting off. Feel free to delete this message once you get to moderating it.
Sincerely,
Shaamaan