low prediction accuracy in a variable state

[safaa]

hello !
when making validation (for unrolled DBN)for target node say A_2 at time= t2;A can have values {a1,a2,...,an}. for A=a3 validation gives accuracy 0(that is DBN fails in predicting this value). how can we know why?
how can we find explanation?

[safaa]

any replay would be appreciated!