We're facing issue (Unable to locate .Net Core SDK) on 4.3 beta while open solution in vs 2019. if you are facing same issue follow below steps.
1. Close visual studio.
2. Run dotnet --list-sdks from the command line. Take note of the greatest version number.
3. Go to root folder of project.
4. Create a global.json file at the root of the solution with the exact version number from step 2. it needs to contain all the digits otherwise it wont work. This is the my version at the time of writing.
{
"sdk": {
"version": "3.1.101"
}
}
5. Then try to open project in visual studio again. And you win :)
Hope this information will help you.
Thanks,
Jatin