The Entity Framework tools version '5.0.6' is older than that of the runtime '6.0.0-preview.3.21201.2'. Update the tools for the latest features and bug fixes. code example
Example: The Entity Framework tools version '5.0.3' is older than that of the runtime '5.0.5'. Update the tools for the latest features and bug fixes.
Use command line, Cmd or PowerShell for specific version:
dotnet tool update --global dotnet-ef --version 3.1.0
or for latest version use (works also for reinstallation):
dotnet tool update --global dotnet-ef