MRW, the MSAA Registration Issue Workaround for JAWS
Doug Lee
Last Revised July, 2025

Note: These scripts are considered legacy by 2025 and have not been tested nor reported on by users since 2018. They are here in case they remain useful somewhere. However, their use is strongly discouraged except where truly necessary, as they may adversely affect JAWS' behavior in apps developed long after these scripts were written.

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. It is not known whether this issue has ever been seen under Windows 11.

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

• Messages in Skype saying that "these scripts do not support this Skype version" even when they do. (Skype was discontinued in July, 2025, however.)
• Difficulties reading Skype chat messages.
• Failure of some custom scripts for Internet Explorer, such as for a specific web page or company website.
• Failure of other custom scripts that use MSAA objects directly.
• Failure of JAWS to announce some incoming system tray notification messages.

Table of Contents

• MRW Script Usage
• Technical Details and Other Solutions
• Release History

MRW Script Usage

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

• If not already done, install the MRW scripts. You can uninstall the scripts thereafter at any time via the new "Uninstall MSAA Registration Issue Workaround (MRW)" item in the Start menu. Typing "mrw" in the Windows 10 Search box should also find this item.
• To check the status of MRW, type Alt+JAWSKey+C. JAWS will announce whether the MRW workaround is active or not active. Active means the MRW scripts will intercept failing MSAA requests and fulfill them as best it can. Not active means the requests will be handled by JAWS without any help from the MRW scripts. The MRW scripts will be inactive by default after every system reboot or JAWS restart. JAWS may also announce a count of cached objects, which merely indicates how many MSAA objects MRW has had to obtain around the MSAA issue.
• On encountering any problem you suspect is caused by the MSAA registration issue, which can occur after any system reboot or JAWS restart, type Alt+JAWSKey+C twice in quick succession. This will toggle the MRW scripts on. Doing this again will toggle them back off. Turning them on may fix problems in various applications and scripts.
• Though this should rarely if ever be needed, you can type Alt+JAWSKey+C three times quickly to force MRW to deactivate, and four times quickly to force it to activate. For both of these, the object cache is also cleared, so no stale information can be used. These two features were added in revision 15.

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 41, released July 24, 2025

• Added a warning against use of these scripts unless absolutely necessary, because they may adversely affect JAWS' behavior in apps developed long after these scripts were written.
• The minimum JAWS version for these scripts is changed from 14.0 to 17.0.
• uia.jsh is no longer included with these scripts, because this could sometimes alter the compilation of other scripts.
• The installer contains version and product information visible from the Details tab in File Explorer, to better identify its contents. There are also other minor installer improvements.
• A "directives" text file is included that provides information on how to install this set of scripts manually. See "Handling Directives Files" in the "Common Script Elements" document for further information.
• There are various code improvements collected over the last seven years, but none that are expected to alter script user experience.
• These release notes are reformatted to match other projects, and there are other minor improvements to this document's content and HTML structure.
• Old history entries in this document section are now hidden inside a details tag that may be expanded to show them.

Revision 24, November 17, 2018

• Should work under JAWS 14 and 15 without a script load error.
• Minor documentation updates.

Revision 21, January 16, 2018

• Reverted to older NSIS installer to fix a few logging and installation problems.

Revision 20, September 12, 2017

• Upgraded to support installation into JAWS 2018.
• A post-install log should appear if the installer fails to find any installed JAWS instances.