I use Android Studio as my IDE in coding Flutter. I was able to create 2 projects before this and it worked absolutely fine. I had to clone a repo from Github. The IDE said
Some SDK versions of Flutter may cause the problem of not being able to find the device or simulator.You can switch the SDK version to the stable version. I had a same problem on my Mac with the Flutter version 1.17.4, and it worked after I went back the version to 1.17.3.
Version rollback step:
1.Open the Flutter GitHub repository.
2.Click 'master' button to open the switch menu. And the click 'Tags' item.
3.Search the stable version tag(e.g. 1.17.3).
4.Open the tag and click the commits.
5.Copy the top commit id.
6.Run the command 'git reset --hard $(commit id)' in the Flutter directory.
7.Restart the Android Studio.