OK, I am running FS2004 and the client option is selected for simmconnect. If it is there then there could be another problem, let's go look at the client options. OK, so what's going on here ? You can clearly see that my flight simulator is running so why is the client not recognising this? The most common problem is that the fsuipc.dll is not in your modules folder, so go take a look and make sure it is. Just a quick walkthrough for those that have difficulties understanding the refuelling or get a Flight Simulator not started warning.