If you are using SharePoint workflows to update SharePoint List items, I am 100% sure that you might have seen the errors given in the below table.

If your answer is YES then go through the root cause for these errors and design your workflows accordingly.

Status / Event Type	Description	Outcome	Possible Cause(s)
Error	The workflow could not update the item, possibly because one or more columns for the item require a different type of information.	Unknown error	If you try and update the same item (though different fields) multiple times in a workflow, it can cause errors.  Essentially the workflow engine has moved on to the second update while the first is still pending. The way around this is to use variables throughout your workflow (one for each field being updated subject to any logic), then do one single update of the list item after all of the logic has run its course.
Error	Error updating a list item	List Item Not Found	No item in the list matching the criteria used to find a list item being updated.
Error	Error updating a list item	Access Denied	Permissions of the user who initiated the workflow don’t allow them to modify data in the list item.
Stopped Event Type: Error	Error Deleting a list item	Access Denied	Permissions of the user who initiated the workflow don’t allow the user to delete items from the list.
Error	Error updating a list item	Unknown Error	Attempting to update Approval Status of a list item from a Workflow initiated by a user without approve permissions on the list/library.
Failed on Start (retrying) Stopped (Event Type: Error)	Error updating a list item	Unknown Error	Incorrect data types. E.g. Attempting to include illegal characters in the filename of a document by appending the date to the filename. Permissions: Attempting to update a list item using the permissions of the user who initiated the workflow, who doesn’t have access to update items in the list.
Error	An error has occurred in		A previous workflow error has caused the workflow to halt.
Error	Error updating a list item	Document must be checked out	The document or list item being updated is in a list or library with force checkout enabled. First check out the document before making changes from a workflow, or disable force checkout. Note: Setting the Approval Status via a Workflow created using SharePoint Designer is not possible when Force Checkout is enabled.