Excel Application Scope: Unable to set Output

Hi there
I have a few .xlsm files to process. It seems that it is not possible to set the Output of “Excel Application Scope” because it will result in the Error:

Could not retrieve the result of the job execution. This might be because a message was too large to process.

The Application Scope seems to work as long as I don’t try to set the scope to a variable. The strange thing is that it worked with the same Excel file last week. I have no idea what could have been changed.
Has anyone experience with that?
btw:
I also saw that there is a property “InstanceCachePeriod” which is undocumented on Activities - Excel Application Scope.

Update: The error appears only, if the workbook is set to an argument. If it is set to a variable, the error won’t appear. I also tested to use “assign” to set out_Workbook = tempWorkbook, which seems to work. This may be a workaround. Simply set a local variable which will be assigned to the argument in a further step.