MRW, the MSAA Registration Issue Workaround for JAWS
Doug Lee
Last revised January, 2018

The MSAA Registration issue Workaround (MRW) scripts for JAWS are a set of scripts designed to help JAWS work around an issue sometimes found in Windows 7, 8.1, and 10 installations. The issue consists of an abnormality in the Windows registration of certain Microsoft Active Accessibility (MSAA) DLL modules, resulting in JAWS being partially unable to use accessibility information in various applications. Example symptoms include

In this author's experience, symptoms tend to appear after a reboot, typically following Windows updates, and can disappear after another such reboot at a later time.

MRW Script Usage

To use these scripts to work around the described MSAA registration issue,

Technical Details and Other Solutions

The MSAA registration issue appears to consist of missing or improper COM registration of one or more MSAA-related DLL files. The impact is that IDispatch (COM Automation) calls to MSAA objects, such as from JAWS script code, fail or return invalid results.

To this author's knowledge, the most common cause of this MSAA problem is the installation and subsequent removal of Mathplayer. Reinstalling Mathplayer tends to fix the issue directly. These scripts are provided, however, for those who do not wish to install Mathplayer and/or who do not have reason to believe Mathplayer has ever been installed.

The effects of the MSAA registration issue can extend beyond JAWS to other screen readers. For example, NVDA may become unable to read some web pages properly and/or start saying "Unknown" on Alt+Tab. These scripts, of course, only address the issue's effect on JAWS and JAWS scripts.

Release History

This section lists changes among MRW releases, most recent first.

Revision 24, November 17, 2018
Revision 21, January 16, 2018
Revision 20, September 12, 2017
Revision 17, May 12, 2017
Revision 14, May 9, 2017
Initial release.