This type of error was seen in one of the DTP load in my project.
System: BW 7.5 on HANA
DTP load: DSO to DSO
The load failed after repeatition of DTP also. There were no error stack records.
The data was transactional and loading from one aDSO to another aDSO.
The type of aDSO was standard DataStore Object.
The DTP was not having HANA execution enabled.
The error comes when multiple packages are processed in parallel by the DTP and it tries to insert records in target in parallel.
The error was resolved after enabling the semantic grouping in DTP.
Hope this helps. 🙂