Can't clone private repo on github from SourceTree

It happens because SourceTree didn't get some private access from Github while authenticating. So the solution is very simple

1. Login into your Github account on any browser
2. From top right corner select SETTINGS
3. Now select DEVELOPER SETTINGS
4. From DEVELOPER SETTINGS select PERSONAL ACCESS TOKEN
5. Now from PERSONAL ACCESS TOKEN select GENERATE TOKEN

6. Fill Note as sourcetree and Check All Scopes from checkbox as show in below screenshots

7. After Click on Generate Token

8. Now Open sourceTree

9. Click on sourceTree preference & Click add Account

10. Select options as shown in below screen shot
11. Enter username as your Github account username and password as Generated Token from Github
12. Click on SAVE now you might see all your repository are visible and can clone too

Hope it helps

I had same problem. My fix way:

1. Remove user from SourceTree settings (optional, i not sure);

2. Add you account in setting and generate new SSH key (it's a main part of fix);

3. Clone your repo;

4. If SourceTree sill can't clone repo you can try to clone from main page of SourceTree choosing external repos.