@chanakyabtc Only thing I can think of is that its a permissions issue. Check that the user you're running siad as has permissions to run siad and read/write permissions to the data directory (WorkingDirectory).
Same problem here.
I also tried to connect to siamining pool trough tcp on (depricated) http port but got a malformed json response. @jacalf did you managed to make it work? if so can you share the solution please :) .