Error: workspace folders from different providers are not allowed

[vsosmakov]

Extension 'Remote FS' failed to update workspace folders: Error: Workspace folders from different providers are not allowed in the same workspace.

Describe the bug
A clear and concise description of what the bug is.

To Reproduce
Steps to reproduce the behavior:

1. Start vscode-insider
2. Ctrl+Shift+p -> "Remote-WSL: New window"
3. Open Folder in Explorer (Ctrl+Shift+E), choose any...
4. Ctrl+Shift+P -> Remote FS: Add Folder to Workspace -> choose...
5. See error:
   "Extension 'Remote FS' failed to update workspace folders: Error: Workspace folders from different providers are not allowed in the same workspace."

Desktop (please complete the following information):

• OS: Windows 10 with WSL (Ubuntu 18.04)
• VSCode Version 1.41.0-insider
  Version: 1.41.0-insider (user setup)
  Commit: bbf00d8ea6aa7e825ca3393364d746fe401d3299
  Date: 2019-12-05T06:56:28.532Z
  Electron: 6.1.5
  Chrome: 76.0.3809.146
  Node.js: 12.4.0
  V8: 7.6.303.31-electron.0
  OS: Windows_NT x64 10.0.17763
• Extension Version Remote FS 0.0.15 - 2019-04-27

[vsosmakov]

I swear it worked for me before