Hi Keyoor,
Since you mentioned a pattern is being followed, if it runs with a process chain it fails and when it is manually set in error and repeated it gets completed successfully.
Whenever a process chain is triggered, except the start variant all other processes are triggered with a specific ID (like BWUSER). You can check in sm37, which ID is being used. Once it is repeated manually, then the system uses your personal ID. Check the roles assigned to that ID (BWUSER) and see if it has enough authorization to perform that step.
Mohamed Shadab