If you specify a custom charset, you must also specify a mask

[b8vr]

First, your mask is wayyyyy to big. Hashcat will not accept that, plus it makes no sense. Second, your issue could be because you put "" around your mask. Don't do that.

Also, is it on purpose that some letters as well as 0 is left out? Otherwise you could just do -1 ?l?u?d ?1?1?1 etc.