用codis-fe界面添加server实例报错，没懂啥意思

{
"Cause": "ERR unknown command 'SLOTSINFO'",
"Stack": [
{
"Name": "github.com/CodisLabs/codis/pkg/utils/redis.(*Client).Do",
"File": "/usr/local/codis/src/github.com/CodisLabs/codis/pkg/utils/redis/client.go",
"Line": 57
},
{
"Name": "github.com/CodisLabs/codis/pkg/utils/redis.(*Client).SlotsInfo",
"File": "/usr/local/codis/src/github.com/CodisLabs/codis/pkg/utils/redis/client.go",
"Line": 232
},
{
"Name": "github.com/CodisLabs/codis/pkg/topom.(*apiServer).GroupAddServer",
"File": "/usr/local/codis/src/github.com/CodisLabs/codis/pkg/topom/topom_api.go",
"Line": 375
},
{
"Name": "github.com/CodisLabs/codis/pkg/topom.(*apiServer).GroupAddServer-fm",
"File": "/usr/local/codis/src/github.com/CodisLabs/codis/pkg/topom/topom_api.go",
"Line": 91
}
]
}