@federeroui
Yes, it is normal for there to be errors... O.B. interprets it as an error because it fails to overcome BLOCK N°...
BLOCKS are the requests that the configuration makes to the server, in your case you cannot see the request number from the screenshot you posted but I imagine it is 1, that is, the first request that the configuration makes to the server.
The error is given because it cannot pass, it could also be the proxy that is not working well.
Some servers work differently than others, it depends on how many transactions they allow you to perform: For some in O.B. status. you will always see that they never go beyond BLOCK 1 but when they find a MAC they go forward in the BLOCKS up to the HIT - Others make you "go through" up to the KEYCHEK (in my case up to request 3) and then give you an error if there is no 'it's correspondence with the MAC, or they give you the HIT as a gift.
I don't know what "config" you use or how it's made, one of the most common mistakes for beginners is to enter the entire URL, for 95% of configurations you just have to enter the domain and port (if there is a port) to example: pickimpickim.ddns.xyz:8080 <--- (fancy URL).
It could also be the MAC if you don't find anything... persist, you'll see that sooner or later you'll find something. If you use proxies, don't use VPN.
Greetings.