You're getting a login error for your report that looks something like this:
"Problem while checking for records in jnDoesReportHaveRecords. Message=The table 'Sheet1_' could not be found. Error in File SomeReport.rpt: The table could not be found."
Our software is unable to open/see the input XLS file when it runs from the scheduler. This is not a bug in our software. It is a "feature" of the operating system.
You might be able to get around it by trying what is in this KB article:
Create these two folders:
Excel needs (expects) these folders to exist if it's not run interactively.