Is it always the same invoices? In other words, if you were to emailing this same invoice again, would it display the same problem?
It also looks like you have no customer selected. This can cause problems, because Manager suppresses empty fields. And the theme used to display the transaction depends on having information in place to know how to apportion space. Or maybe that’s another result of the problem.
Also, are your business details always the same? Or did you edit them for this invoice as compared to others that work? If so, you might have an invisible character that is forcing the program to allocate too much space to the right of the vertical scribe line.
Finally, when you referred to emailing a PDF, that could have meant a couple different things. How exactly did you obtain this image?