If your error code starts with a ‘v’, then your connection is not being supported because of a suspicious IP address. This is most commonly caused by using a VPN, but also providers that lower or otherwise alter your IP or ping or any other third party software are being blocked by this protection. These IP addresses are permanently blocked, but know that the block entirely rests on your IP address and not on your account.
If you need more information then I highly recommend reading this helpdesk article :
https://help.cubecraft.net/en/article/blocked-connections-aod7sq/ - Or you can create a conversation with me or another staff member if something is still unclear :)