Weird behaviour

[archiif]

I'm trying to download from individual channels, but I keep getting this error:

pullcord -t xxxx -c 566527119652290568 -history
2020/01/23 02:19:59 [DG0] wsapi.go:540:onEvent() error unmarshalling READY event, json: cannot unmarshal number into Go struct field ReadState.last_message_id of type string
2020/01/23 02:20:20 [566527119652290566] error getting members from 0: (*discordgo.RESTError) HTTP 403 Forbidden, {"message": "Missing Access", "code": 50001}

But I do have access to that channel. And soon after I instantly get blocked by Discord:

pullcord -t NDc1NjI2NjEzODMzMzM0Nzg3.XiCj9A.GoLxRH3fq4yBNR1rh2_NyLxAyBI -c 566527119652290568 -history
2020/01/23 02:22:08 [DG0] wsapi.go:540:onEvent() error unmarshalling READY event, json: cannot unmarshal number into Go struct field ReadState.last_message_id of type string
2020/01/23 02:22:09 error getting guilds:HTTP 403 Forbidden, {"message": "You need to verify your account in order to perform this action.", "code": 40002}

Note that I'm using a non-bot account.