Hi Albert,
>I have a loop that is used for processing the worksheets in a workbook....I am getting occasional errors showing up in the logs >saying property SHEETS cannot be found.
I have had no problem over the last few years in such situations. But sure I understand there may be situations where access to the sheets may be at risk. However, the code we run is definitely short and the COM calls are a couples of seconds in most cases.
So no silver bullet here. But I'd be definitely wary about MS-Excel COM heavy -duty work especially in server-based activity. In such cased I'd consider some external stuff such xlsgen which may be easier to control. It's definitely fast and server-ready. One caveat though with this standalone library: it's fast and great on midsized worksheets. Loading very large documents just takes more time than the in-house MS-Excel code... It will really shine on anything compact xl-stuff, at least on my test cases.
Daniel
https://xlsgen.arstdesign.com