We found, due to the recent Windows Update, jscript9legacy.dll was getting used instead of jscript.dll (per this reference: Script errors in Working Papers Caseview - Windows 24H2 Update). According to Caseview, "jscript9legacy.dll does not contain the full functionality" as jscript.dll.

Using Solution 2 from the reference above, we created a new registry key to load "jscript.dll" as default instead of the replacement DLL "jscript9legacy.dll".

Now when we call the Server Side JavaScript function, we no longer get the specified error.