I connected to the PI server through the PI SDK tool, but encountered an error while connecting

I have encountered a problem and request support:

I connected to the PI server through the PI SDK tool and encountered an error message saying 'Connection to server failed: Exception from HRESULT: 0x80040402'.

Other information:

The PI server has undergone HA and has a total of two IP addresses;

2. The PI server version is 2018;

3. I can successfully ping the PI server address;