I recently needed to add some colors to a batch file output. And for this you have to enter Virtual Terminal Sequences starting with ESC (ASCII 27) See: https://msdn.microsoft.com/en-us/library/windows/desktop/mt638032(v=vs.85).aspx
In WeBuilder this character shows up as a rectangle, but only half the width of the regular characters.
This screws up the cursor positions on the line with the ESC characters.
I ended up having to edit the file in UltraEdit as that displays the ESC in similar fashion, but the width is the same as regular characters. (It just have some extra space on the right side of the character)