Opening a CR created this error:

Error Type:
Microsoft JScript runtime (0x800A138F)
'OSList' is null or not an object
cr.asp, line 341


....

CPUList = FCApp.GetHgbstList("CR_DESC");
CPUList.MoveFirst;
while (! CPUList.EOF) {
Response.Write("CPUArray[" + i + "] = new Array();")
OSList = FCApp.GetHgbstList("CR_DESC",CPUList("title"));
// Exclude inactive elements
OSList.filter = "state <> 'Inactive'"; ---- line 341

The behavior is different between fcfl and the fcsdk.
In fcfl, if the list level has no elements, the method returns an empty recordset.
In the fcSDK, it appears to return null. Hence the error: 'OSList' is null or not an object.

The workaround is to fix the user-defined list, so that you don't have any empty levels.

CR 2212 has been opened for this issue in the fcSDK