If your PDF document only contains
this is likely due to invalid characters or commands in one of your Sections.
Please check the following:
- Try to remove uncommon characters.
- If you copied parts from e.g. PDF documents, the text often contains invalid characters that can't be represented in text form.
- If the PDF generation used to work, you can use the history feature to restore previous states.
In any case, please send an email to email@example.com and a description about the cause.