What is the subject of the verb "miss" in this sentence?
This is a common misconfiguration for environments that are supposed to install DNS on every DC, but miss some.

Question

What is the subject of the verb "miss" in this sentence? 
This is a common misconfiguration for environments that are supposed to install DNS on every DC, but miss some.

Answer

All of you wrong! The subject of the verb "miss" is 'that"; from the clause preceding it:
"..that are supposed to install DNS on every PC, but (that) missed some."
Of course, the "that" in the second clause refers to the "environments" of the first. Here is the sentence in full:

This is a common misconfiguration for environments 
that are supposed to install DNS on every PC, 
but (that) miss some.

That should clear it up.

Answer

environments

Answer

'Environments' is the subject.

Answer

environmentalists is the subject
if i understood it right

Answer

hey
environments or environmentalists