7 64 win in the .Net Core installation after 2.1 x86 SDK, uninstall and re-install the .Net Core 3/2 x64 SDK. No results .Net Core 3.1 SDK when creating a new project in VS.
Dotnet --info run in cmd, .Net Core SDKs installed No SDKs were found inside tips
This is due to the environment variable, configure the C: \ Program Files (x86) \ dotnet and C: \ Program Files \ dotnet. Lead to the implementation of dotnet run command is C: \ Program Files (x86) \ under dotnet.
In the environment variable to C: \ Program Files (x86) \ dotnet canceled. After the re-run dotnet --info returned to normal, .Net Core SDKs intallled in SDK 2.1 and 3.1 have been.
Reopen VS New projects are also normal.