I’m a Web Designer and when I open some PSD files in my Photoshop CS3 (Windows 7) I get these messages pop-up before to open PSD. My fellow designer use Photoshop on Mac OSX.
Error 1
Some text layers contain fonts that are missing. These layers will
need to have the missing fonts replaced before they can be used for
vector based output.
Error 2
Some groups were found corrupted and repaired.
Error 3
This document contains unknown data which will be discarded to keep
layers editable. To preserve the origional appearance instead, choose
Flatten to load composite data as a flattened image.
Answer
Error 1 This particular message is not significant. It just means that the font file you have is not the same version as your colleague’s, and there’s no harm in telling PS to update the layers. A “Missing Font” error is more important; it means he used a font you don’t have. That would be handled by having the designer either rasterize or outline (convert to shape) all font layers before sending the file to you. Since you don’t need to edit the text, it doesn’t matter whether it’s actual text or just a shape.
Error 2 probably means exactly what it says, and is for information only. Photoshop has already repaired the problem.
Error 3 tells you that your designer has a more advanced version of Photoshop (a later version and/or Photoshop Extended) and has included features that your version doesn’t recognize. Smart Filters or 3D layers would be examples of this. A few minutes of dialog between you would probably identify these quite quickly. If you upgrade to CS5.1 or CS5.1 Extended you won’t see this one again.
Attribution
Source : Link , Question Author : Jitendra Vyas , Answer Author : Alan Gilbertson