I know this is an old issue -- I may even have posted about it before, but I can't find it here. I have Sibelius Ultimate with the House Styles installed, Vienna Ensemble, Vienna Instruments Pro. I've written for two different ensembles (string quartet, 4-part choir), with no problems. For a new project, I'm using a "classical symphony" config, with 6 woodwinds/brass instruments, tympani, and the usual 5 string sections.
I've walked through the setup of a manual sound set several times. I added each instrument using VIP in VE, with the correct channels. In the Sibelius config/"manual sound sets" setup, I have a Vienna Ensemble instance selected, and the 12 channels I'll be using set up and configured. Every "Test" in Sibelius plays the correct instrument in VE.
The strings play correctly from the score itself, but no other instrument does -- all the woodwind and brass (even the tympani) trigger the 1st violin in VE (channel 8). I've even reassigned every instrument in Sibelius's Mixer, with no help. I have two VE setups now configured through Sibelius, and both have exactly the same problem. Where do I look? What have I missed?