Unspecified running error while programing WeMos D1 in wireless mode
You might have Python installed, but can you run it?

Open a command window on you PC.  (Windows button R then CMD)
Then in that type python.

If python starts up then it should be working, but I suspect you will get an error saying:

'python' is not recognized as an internal or external command, operable program or batch file.

To fix this you need to edit you path and restart the IDE.  (How you edit you path depends on your version of Windows so you would be best searching for edit environment path and your version of windows and that should come back with an answer quickly.

Of course if its Linux/mac then it could still be the same issue.