Can't figure out what this one line display is at the top of my .erb file.

Above the first line of any ERB file is now this 1.5 line high display and I don't know what it is or how to get rid of it.

Here is a screenshot: https://www.evernote.com/l/ABPaz0_4YQ5GOIZ1ZL7dfNPjCIbKLj6_DXQ

In this screenshot, you see a highlighted <%=

What is this and how do I get rid of it?

Many thanks,
Wes