请问，为什么无法添加用户，提示如下，该怎么办呢？

跟踪信息 (最近一次调用): File "/usr/local/bin/xray", line 8, in sys.exit(menu()) File "/usr/local/lib/python3.6/site-packages/v2ray_util/main.py", line 254, in menu user_manage() File "/usr/local/lib/python3.6/site-packages/v2ray_util/main.py", line 171, in user_manage multiple.new_user() File "/usr/local/lib/python3.6/site-packages/v2ray_util/util_core/v2ray.py", line 20, in wrapper result = func(*args, **kw) File "/usr/local/lib/python3.6/site-packages/v2ray_util/config_modify/multiple.py", line 90, in new_user nw.create_new_user(**info) File "/usr/local/lib/python3.6/site-packages/v2ray_util/util_core/writer.py", line 617, in create_new_user user["flow"] = kw["flow"]