another funny moment of entity framework is here! This fuc* up comes when you want change .net Core version to 3+. If we then try to run the update or add migrations command, we get an error.

$ dotnet ef
Could not execute because the specified command or file was not found.
Possible reasons for this include:
  * You misspelled a built-in dotnet command.
  * You intended to execute a .NET Core program, but dotnet-ef does not exist.
  * You intended to run a global tool, but a dotnet-prefixed executable with this name could not be found on the PATH.

How to fix it? Easy! You need to reinstall dotnet-ef tool, ideally globally. The way how to do it is easy, use this command:

dotnet tool install --global dotnet-ef

Once you've done so, you should be able to run your dotnet ef commands successfully.

I hope this post helps someone, or feel free to share.