When planners are running ATP the SL field is empty and the below error appears:
Error in calling up function 'BAPI_APOATP_CHECK'
Error in calling up function 'BAPI_APOATP_CHECK' in APO server 'C40CLNT100': connection closed (no data)
Message No. AG023
A system error or communication error occurred while calling up a
function in the APO server.
Inform the relevant system administrator or SAP Support.
Please advise how we could solve it?