自己修改别人的urdf文件，用moveit 配置助手生成了Demo.lanuch，运行之后在rviz里面可以看到机械臂，但是报错了，具体错误如下

[ERROR] [1617752615.735037382]: Group 'arm' is not a chain

[ERROR] [1617752615.735223971]: Kinematics solver of type 'kdl_kinematics_plugin/KDLKinematicsPlugin' could not be initialized for group 'arm'

[ERROR] [1617752615.735414230]: Kinematics solver could not be instantiated for joint group arm.

[ WARN] [1617752615.850870497]: The root link base_link has an inertia specified in the URDF, but KDL does not support a root link with an inertia. As a workaround, you can add an extra dummy link to your URDF.

[ERROR] [1617752616.291773005]: Client [/move_group] wants topic /move_group/goal to have datatype/md5sum [moveit_msgs/MoveGroupActionGoal/689f0d7213d5960a2a9e9b117a0fdb73], but our version has [moveit_msgs/MoveGroupActionGoal/6514728724a6f4ce3f2f5a26db255bc9]. Dropping connection.

[ERROR] [1617752645.935486956]: Unable to connect to move_group action server 'move_group' within allotted time (30s)

哪里出了问题？是urdf的问题还是我运行配置助手配置的问题？

我的urdf文件和srdf文件在这  （因为文件内容太长不好复制）