PDF opens as gray screen in browser | Reader, Acrobat 10.1.2

Issue
End user (client-side) solutions
Solution 1: Update to Acrobat or Reader 10.1.3
Solution 2: (Not required if you update to Acrobat or Reader 10.1.3)
IT-Admin (server-side) solutions
Additional information

After you install 10.1.2, a PDF viewed in Internet Explorer appears as a blank page. Display problems could have a number of causes. This article addresses only a specific issue with 10.1.2. The free 10.1.3 update to Acrobat X and Reader fixes this issue.

The 10.1.3 update to Acrobat X and Reader addresses this issue. You can install it automatically from within Acrobat X or Reader.

Open Acrobat or Reader.

Choose Help > Check For Updates.

Acrobat or Reader installs the update automatically.

If you prefer, you can download and install the update yourself. Click the appropriate link below and locate the 10.1.3 update.

Reader updates (for Windows)

Reader updates (for Macintosh)

Acrobat updates (for Windows)

Acrobat updates (for Macintosh)

Do one of the following:

Download and open the PDF in the stand-alone product. Always works.
Refresh the PDF (press F5). Works sometimes.
Reinstall 10.1.1. Always works.
Install the patch for 10.1.2 products as follows:

Close Acrobat and/or Reader.

Download the patch from AdobeAcrobatReaderPatch10.1.2_cpsid_93026.zip.

Extract (unzip) the download to any location.

Double-click the extracted EXE to run it.

Restart your computer.

Note: Run the patch in silent mode by specifying the -silent flag on the command line. Open the command prompt ‘As Administrator’ to avoid a UAC prompt dialog. For example: <path to patch> -silent. Silent mode suppresses all dialog boxes, error messages, and the success message. The patch adds a log file to %temp%\AcroPatchApplication1012.log.

These solutions are designed to help IT resolve web-based PDF display issues in the B2C case. In this case, end users (usually customers) reside outside the IT-managed network (where the above mentioned client side solutions cannot be implemented).

Display problems could have a number of causes. The following workarounds only apply to 10.1.2. They apply in cases where PDF display fails because the product can't determine the length of the PDF file based on information contained in the HTTP header.

Possible workarounds include:

For zipped files, remove accept-ranges from the HTTP header. This method should have zero effect on any site or site traffic. Cons: none.
Do not zip PDF files and return content-length in the header of the HTTP response. For example, on Apache: \.(?:gif|jpe?g|png|pdf)$ no-gzip. Cons: Can increase web server traffic and sometimes involves changing CGI code.