Install the latest patches for both ALM & Sprinter.
Are you using default QC port 8080 or have you changed this?
if you have changed this, you need to make changes in sprinter config files (Sprinter.exe.config SprinterAgent.exe.config
& SprinterRTE.exe.config)
What's your OS?
Are you trying to connect to sprinter from same machine you have ALM server running?
Did you try to connect from some other machine and check if you get same error?