I am working with a drawing and changed a lot of content and successfully exported to PDF.  All the changes are visible.  I saved all files DWG and PDF.  A few days later when I added new text I can see it in the DWG version but not the PDF.  I can change text content that previously was there and the chnage is visible in the PDF but if I copy that text and paste it it is not visible.  The properties of both sets of text appear to be the same.

DS V2.12 Windows Home Premium.  Love DS!!.