objSpread2 missing error in "excelcompare"
a) Your screenshot references ExcelCompare.tcx script extension, while the referenced help article talks about ExcelSheetCompare.tcx one;
b) Script extensions are .zip archives, so you can open them and examine their internals to understand the source of the problem;
c) objSpread2 variable in the ExcelCompare.tcx script extension is initialized with this line of code:
Set objSpread2 = objExcel.Workbooks.Open(secondFile)
So for me it looks like that Excel failed to open secondFile file and thus you got an error that objSpread2 object is required later in script extension code.