OL98: (IMO) ErrMsg: The Rsabase.dll Does Not Match the Signature (193002)

NOTE: These procedures only apply if you have installed Outlook with the Internet Mail Only option. To determine your installation type, click About Microsoft Outlook on the Help menu. If you have the Internet Mail Only option installed, you see "Internet Mail Only".

For information about the differences between Microsoft Outlook and Microsoft Outlook Express e-mail clients, click the following article number to view the article in the Microsoft Knowledge Base:

257824 OL2000: Differences Between Outlook and Outlook Express

SYMPTOMS

During setup of Microsoft Outlook 98 IMO, if you choose to replace newer files with older ones, you may receive the following error message:

CAPI: The install failed. The rsabase.dll file that is being installed doesn't match the signature file or the value in the registry.

Click OK and Setup will report that it was successful.

NOTE: This issue only occurs if you have Microsoft Windows NT 4.0 and Service Pack 4 installed.

CAUSE

Outlook Setup overwrites the files Rsabase.dll and Rsaenh.dll. This is done during the installation of the Microsoft Internet Explorer 4.01 components.

RESOLUTION

To fix the problem re-install NT 4.0 Service Pack 4. This will update the overwritten files with the correct versions.

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.

MORE INFORMATION

During setup of Outlook you are asked if you wish overwrite the files, Rsabase.dll and Rsaenh.dll, with older ones. If you click Yes, the error message will appear. Once you click OK, Setup will finish and will prompt you to restart.

The setup program leads you to believe that the installation was successful. In fact, the files installed by Internet Explorer 4.01 render S/MIME inoperative.