Error message pointing to a line in EC_EXTEND with <! at the start.  Why does it occur?

Newer versions of Motion Perfect require the correct syntax for XML comments.

For example:

      <!-- CoE CW (2), Target Pos (4), Touch probe (2), Digital outputs (4) -->

Older Motion perfect versions allowed the old format that is actually wrong.

Like this:

      <! CoE CW (2), Target Pos (4), Touch probe (2), Digital outputs (4) >

You can also see the reason in this tutorial: