SPOOL INTERNAL ERROR is very common in SAP landscape. whenever spool reaches to their limit so it’s start failing the jobs & prints & due to this everything get stopped in SAP system.
SAP is having a default limit of 32000 spool in SAP system as per SAP Note 48284.
You need to check the limit by logging into 000 client – SNRO – Object – SPO_NUM & check interval.
if there is an heavy usage of SPOOL in your organization. you can use 2 things to resolve the issue.
1. Schedule daily cleanup job (RSPO1041) in the system with variant value less then 7 days.
2. Increase the limit of spool count from 32000 to 60000.
if you system is having this issue & you are not able to run the report in background, then delete the old spool in DIALOG mode for temporary cleanup via SPAD. once it’s clean then you can schedule the job again with change variant.