Constant Error messages and crashes

I purchased a copy of Cubase 9 Pro and then upgraded to include Groove Agent 4, Halion 6 (with sonic) and Grand Se 3. Then made the mistake of loading Dorico 1 to see what it would be like. Now keep getting a message about Halion Symphonic Orcehestra Factory Presets 1 not being loaded. Uninstalled Dorico and it still appears. Now whenever I try to add a Halion Sonic instrument the whole thing corrupts and and I get the ‘save your project under a different filename and restart’ message. Bitterly disappointed at how unstable Cubase 9 is now.