31370: Mac OS: "Can't Open Preferences File" Message covers what to do when a Control Panel's preferences becomes corrupt. The short answer is, trash the offending prefs file.

If that happens, never fear—open the preferences file in a text editor, such as TextEdit. Look for these lines: ...

The Accounts System Preferences pane may not be the most glamorous destination in Mac OS X, but it?s definitely worth a stopover in Leopard (Mac OS X 10.5). Check it out and you?ll find a ...

Open the Preferences file with either a text editor like Notepad or an app like Microsoft’s Visual Studio Code.