Devon,
Retried today and it works as expected.
I had just set my 2018 license and had not rebooted when I got the error. Yesterday I was getting red text and a syntax error doing x=x$ and vice versa on line one and two with line numbering off, (my normal), and could save the program with warnings. Since it was all syntax errors on save, it was blank on re-opening. I think the 2018 was a Direxions version so perhaps it updated, or a reboot corrected the issue.
Otherwise very convenient indeed as this is one of the few typos I am prone to make in UltraEdit text coding and should fix itself on pasting.