To answer the two questions you present:
- Which one is correct?
The corrected version is correct. "nor" isn't appropriate there.
- Are those equivalent?
My answer to the first part answers this. They are not equivalent, as the original version uses "nor" in an incorrect way.
You've picked a very tricky word to use. "Nor" is the sort of thing that even I shy away from because its use cases are tricky.
You'll OFTEN find "nor" used with "neither":
Child: Mother, I'm hungry!
Mother: I know child, but alas, we have neither milk nor bread!
That example that I typed up might look weird to you - and for good reason. It's a more stuffy construction that feels very old to me (which is why I threw in the "alas" - that's the sort of connotation I have for "nor").
"nor" seems to exist to solve the problem that arises with our language due to logic. Without "nor," we would have (in the previous example), "we have no milk or bread." Technically speaking, this says that we don't have one of them, and says nothing about the other. The mother wants to be clear to the child that she has neither the milk nor the bread.
The actual reason that "nor" was incorrect in your post was because you didn't use the correct construction of "neither" and "nor."
You could have either had
However, there's no link or button to do that.
OR
However, there's neither a link nor a button to do that.
The first one is much more colloquial and makes more sense in almost any context today.