。
Following instinct often leads you astray.
Literal
Instinct [target-に] follow [conditional-と] path [object-を] err thing [subject-が] many.
本能に従う ('to follow instinct') — 従う (したがう) takes に for what is followed. 道を誤る ('to err on the path' = 'to go astray') is a literary expression. ことが多い ('it is often the case') wraps the whole observation in a frequency statement.