The root object is missing or invalid

I have been experiencing the same problem, opening a PDF file from a local HTML page. The PDF file can be opened directly in Adobe Reader, so it is not damaged. The problem appears when the PDF file is opened from a link in an HTML document. Following the error message is what appears to be a path: Local\<some string>, where <some string> is an apparently random collection of characters. In other circumstances (a different version of our software), I get the message "The file is damaged and could not be repaired" followed by a similar path. The error occurs when opening any of our PDF files from a link in the HTML documents. The PDF files can be opened successfully when opened directly, or when opened via a link from some other PDF file. My OS is Windows XP SP3, 32-bit machine. I am using Adobe Acrobat Pro 10.1.1; I've tried Firefox 3.6.18 and Internet Explorer 8.0.6001.17602 My colleagues are using a variety of other machines (Vista, 7) with Adobe Reader.

It sounds to me like the failure occurs when trying to read the temporary downloaded version of the PDF file. The source file itself is not damaged, because I can open it in Reader/Acrobat but the copy that Reader or Acrobat is trying to open appears to be damaged. Given that the same error occurs with IE as with Firefox, I'm doubtful that the problem is the browser. Any information would be appreciated.

Ken Dyall.