Diagnosis
At the moment MS Excel is not repsonding or is damaged. This typicallyoccurs when you were executing an activity in Editor mode. But therecould also be a serious error with Excel.

System Response
No data could be read from MS Excel; the activity could not beexecuted.

Procedure
Try to execute your last action again. Make sure that you are not inthe Editor mode in Excel (you can find information about the status ofExcel in its status line, for example). If you cannot correct the errorin this way then you will have to terminate manual planning or theprocessing of the layout.
Very rarely Excel still does not repsond after terminating the activity.Then no other layouts can be processed or displayed and also no manualplanning can be executed. In this case exit manual planning and startagain. If this is not sufficient then please close the session in whichthe error occurred.
If MS Excel still does not respond, log off the system and check yourExcel installation. A simple reason for the error might be that youare trying to use manual planning functions without having MS Excelinstalled on your PC.