"Internal Error 2753" appears when installing the Messaging Security Agent (MSA) of Worry-Free Business Security (WFBS)

- Updated:
- 30 Dec 2019
- Product/Version:
- Worry-Free Business Security Standard/Advanced 7.0
- Worry-Free Business Security Standard/Advanced 8.0
- Worry-Free Business Security Standard/Advanced 9.0
- Worry-Free Business Security Standard/Advanced 9.5
- Platform:
- Windows 2003 Home Server
- Windows 2003 Small Business Server
- Windows 2003 Standard Server Edition
- Windows 2008 Essential Business Server
- Windows 2008 Small Business Server
- Windows 7 32-bit
- Windows Vista 32-bit
- Windows XP Professional

Summary

When installing or reinstalling the MSA, you get the following error:

Messaging Security Agent failed to be installed on the Exchange server: sunmail
The operation will continue until it is completed even if the window is closed.
Internal Error 2753: instISDeferredCustomActionSt

Internal Error 2753

Details

To resolve the issue:

Open the Registry Editor (regedit.exe).

Always back up the whole registry before making any modifications. Incorrect changes to the registry can cause serious system problems.
Delete the following registry key:

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Installer\UpgradeCodes
\F79BAC82EE02C8A4CB43EE3AB234B806]
Reinstall the MSA.