So today i try to migrate from asp.net core RC2 to RTM, here’s the step i do when migrating

1. Uninstall all Microsoft.NET Core RC2 Runtime, SDK, and Tooling Preview 1
2. Install the new Microsoft.NET Core RTM, SDK, and Tooling Preview 2
3. Change all version in project.json from 1.0.0-rc2-final to 1.0.0
4. Change all version in project.json from 1.0.0-preview1-final to 1.0.0-preview2-final
5. Find global.json in your solution root, and change it from 1.0.0-preview1-002702 to 1.0.0-preview2-003121
6. Done rebuilt the solution!
7. Good Luck!!