We suddenly ran into the problem last week that whenever we use an Excel viewer to open the final file, we are getting this error message from Excel: We couldn't open this file because it doesn't meet the security standard set by your organization

Our IT changed some security settings recently, that old .xls file type files cannot only be opened and viewed but not edited any more, but since this should anyway be an .xlsx file it should not be affected by this. We also tried to locate the temporary file, copied it to the client PC and tried to open it directly, and this worked without any problems. So somehow this last step of the Excel viewer to open Excel does not work anymore, basically out of nowhere. I was working with PP without any problems and suddenly it started, from one minute to the next.

Any ideas what could be the issue and how to solve this? As a workaround we are now using the Excel writer, but view would be more convenient to use.