Happened to me just now, but I think I identified the cause. I’m using 4.6.1.
I was formatting text to print out two values to screen. I used the standard Format Text → Print String nodes.
Anyways, when I was typing the parameters, I did x first via “x={x}”. It created the X node to connect to it. Then I changed it to “x={x}, y={y}” and somehow the x part got nuked, and just a y node appeared to connect to it. Then I typed it again, and this time, both nodes showed up, but in reverse order “x={x}, y={y}” in the format, but y and x nodes in that order. I wired up the rest, and boom – compile error.
Restarting the project fixed it and the x and y values were in the proper order and it worked.