You did not include any information on your OS level or the actual error message. You really need to give more detail other than "error msg" . There are thousand of various error messages any cell phone can give.
These links may relate to the issue. KB29083-No option to view PDF files when opening a link in the Browser on a BlackBerry smartphone running BlackBerry 6 or 7 KB23496-When opening a PDF file in PDF To Go, the pages are shown only with a red X.