fix #4159

lib/simple_config.py

@@ -233,6 +233,10 @@ class SimpleConfig(PrintError):
             return path
 
         # default path
+        if not os.path.exists(self.path):
+            raise FileNotFoundError(
+                _('Electrum datadir does not exist. Was it deleted while running?') + '\n' +
+                _('Should be at {}').format(self.path))
         dirpath = os.path.join(self.path, "wallets")
         if not os.path.exists(dirpath):
             if os.path.islink(dirpath):