create user extensions directory if not exists

modules/extensions.py

@@ -10,6 +10,8 @@ extensions = []
 extensions_dir = os.path.join(paths.data_path, "extensions")
 extensions_builtin_dir = os.path.join(paths.script_path, "extensions-builtin")
 
+if not os.path.exists(extensions_dir):
+    os.makedirs(extensions_dir)
 
 def active():
     return [x for x in extensions if x.enabled]