It looks like its an amt sending error...I used the terminal to work it out and the amt you enter is not what is in your wallet and is expecting a unit which is all a bit confusing but got there in the end.
The smallest unit of siacoins is the hasting. One siacoin is 10^24 hastings. Other supported units are:
pS (pico, 10^-12 SC)
nS (nano, 10^-9 SC)
uS (micro, 10^-6 SC)
mS (milli, 10^-3 SC)
KS (kilo, 10^3 SC)
MS (mega, 10^6 SC)
GS (giga, 10^9 SC)
TS (tera, 10^12 SC)
When this happens, it usually means that one of the siad modules is taking longer than usual to load (the api loads last so the UI just shows loading until it's finished). Try leaving it loading for a bit (15+ minutes) and see if it starts.
Did you mean a GeForce 960M? The 9600 is close to a decade old and is incompatible with the gpu-miner. If it is indeed a 960M than you may be better off trying the 3rd party cuda miner optimized for Nvidia cards: https://github.com/KlausT/Sia-CUDA-Miner/releases