- VSCode Version:1.28.0-insider(system setup)
- OS Version:Win10
Steps to Reproduce:
1.F1->Type and select ' Preferences: Open User Settings' -> Type and select 'Workbench: Color Theme' -> Select 'Default Light+'.
2.Open and select one folder including one folder at least in Explorer.
3. Check the expand icon before the sub-folder.

Does this issue occur when all extensions are disabled?: Yes
Steps to Reproduce:
1.F1->Type and select ' Preferences: Open User Settings' -> Type and select 'Workbench: Color Theme' -> Select 'Default Light+'.

2.Open and select one folder including one folder at least in Explorer.
3. Check the expand icon before the sub-folder.
Does this issue occur when all extensions are disabled?: Yes