I'm having troubles opening this file with Acrobat on my Samsung Galaxy tablet : it doesn't show greek characters
this is the dopbox link of the file and you can see how the Dropbox pdf reader shows the same file correctly
here is how I see the file with dropbox pdf reader :
ad here is how I see it with Acrobat
Could you please confirm the source of the file, or what was the application used to create the actual file?
Assuming, that the difference in the font that you see because of the actual font(Greek character) that was used to create the file is not embedding.
Kindly refer to the help document PDF fonts, Adobe Acrobat