宝塔中的frp添加服务器出错

我用的是免费的服务器，尝试了好多个都是这样的问题。centos8也试过出会出类似的问题，现在是centos7.7.买了宝塔中的FrpC客户端插件，就是没法添加服务器。请教下有谁碰上过这样的问题。



抱歉，出错了：
Traceback (most recent call last):
File "class/panelPlugin.py", line 1675, in a
return eval(execStr)
File "", line 1, in
File "plugin/frpc/frpc_main.py", line 232, in Server_Add
self.Server_Connect(ServerID)
File "plugin/frpc/frpc_main.py", line 255, in Server_Connect
config = json.loads(public.ReadFile(self.__plugin_path + 'frp_client/config/' + ServerID + '.info'))['server']
File "/usr/lib64/python2.7/json/__init__.py", line 338, in loads
return _default_decoder.decode(s)
File "/usr/lib64/python2.7/json/decoder.py", line 366, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
TypeError: expected string or buffer

:

没人碰上过么，大神帮看看什么问题呢