Unable to create a flowVar

[NameUndefined]

Hi Im making a discord invite checker, it returns a custom type called "Guild", 
but while spawning the procedure the compiler complains:
    
    
    Error: cannot create a flowVar of type: Guild
    
    
    Run

Here is the code: 
    
    
    import json, httpclient, threadpool, strformat
    
    type
        Guild = object
            name: string
            desc: string
            inviter_name: string
            inviter_discrim: string
            channel: string
    
    var guilds: seq[Guild]
    
    proc check(code: string): Guild {.thread.} =
        let client = newHttpClient()
        let content = client.get(&"https://discord.com/api/v9/invites/{code}";)
        if content.status == "200 OK":
            let json_content = parseJson(content.body)
            let
                guild_name = json_content["guild"]["name"].getStr()
                guild_welcome_desc = 
json_content["guild"]["welcome_screen"]["description"].getStr()
                guild_inviter_name = 
json_content["inviter"]["username"].getStr()
                guild_inviter_descrim = 
json_content["inviter"]["discriminator"].getStr()
                guild_invite_channel = json_content["channel"]["name"].getStr()
            
            
            result = Guild(name: guild_name, desc: guild_welcome_desc, 
inviter_name: guild_inviter_name, inviter_discrim: guild_inviter_descrim, 
channel: guild_invite_channel)
    
    let some_guild = spawn check("gtyt4zido")
    guilds.add(some_guild)
    
    
    
    Run

Thanks for your help