It may be that the font-file relating to the font that was used to create the document has become corrupted.
A quick way of checking if that's true is to highlight the whole page and select a different font to see if the document then becomes legible.
Hopefully that's all it is. That's not nearly as serious as the file itself being corrupt.
A quick way of checking if that's true is to highlight the whole page and select a different font to see if the document then becomes legible.
Hopefully that's all it is. That's not nearly as serious as the file itself being corrupt.