If you see this message while trying to run a PlatformIO task like Build or Upload:
No tasks to run found. Configure tasks...
you can fix that easily: Open Preferences: Open settings (JSON) in Visual Studio code (the default keybinding to open the action menu is Ctrl+Shift+P).
Then look for this line:
"task.autoDetect": "off"
and delete it.
Now save the file. You can immediately run PlatformIO tasks after saving settings.json without restarting Visual Studio Code !