Completion doesn't work on nvim with coc

[FalcoGer]

When I try this configuration with Coc

        "sql": {
            "command": "/usr/local/bin/sql-language-server",
            "args": [
                "up",
                "--method",
                "stdio"
            ],
            "filetypes": [
                "sql",
                "mysql"
            ],
            "settings": {
                "sqlLanguageServer": {
                    "connections": [
                        {
                            "name": "****",
                            "adapter": "mysql",
                            "host": "localhost",
                            "port": 3306,
                            "__comment_GRANTS__": [
                                "SHOW DATABASES ON *.*",
                                "SHOW VIEW ON *.*",
                                "SHOW_ROUTINE ON *.*"
                            ],
                            "user": "sqlls",
                            "password": "****",
                            "database": "mysql",
                            "projectPaths": ["/"],
                            "ssh": {
                                "user": "****",
                                "remoteHost": "****",
                                "dbHost": "127.0.0.1",
                                "port": 3306,
                                "identityFile": "~/.ssh/id_rsa"
                            }
                        }
                    ],
                    "lint": {
                        "rules": {
                            "align-column-to-the-first": "error",
                            "column-new-line": "error",
                            "linebreak-after-clause-keyword": "off",
                            "reserved-word-case": [
                                "error",
                                "upper"
                            ],
                            "space-surrounding-operators": "error",
                            "where-clause-new-line": "error",
                            "align-where-clause-to-the-first": "error"
                        }
                    }
                }
            }
        }
    },

and I type anything, coc throws me this error:

[coc.nvim]: Uncaught exception: Header must provide a Content-Length property.

I tried granting select, but that didn't help either.