One of our client is seeing this issue in their production org. Following is the line where this issue is occuring :
ID batchId = Database.executeBatch(MainBatch);
This line is throwing
System.StringException : Invalid Id 000000000000000
There is a scheduler which periodically executes this batch and scheduler is running by a System Admin user, so it has all the permissions.
Has anybody ever faced such issue? And is their any solution for this? In this case we do not have any use of batchId variable so I will definitely remove that which I think would fix the issue but if anyone has more information, please share.