How to fix a SharePoint workflow returning “Error Occurred” due to being unable to update an item

You could use some extension method to update item silently.

public static class SPListItemExtensions
{
/// <summary>
/// Provides ability to update list item without firing event receiver.
/// </summary>
/// <param name="item"></param>
/// <param name="doNotFireEvents">Disables firing event receiver while updating item.</param>
public static void Update(this SPListItem item, bool doNotFireEvents)
{
    SPItemEventReceiverHandling rh = new SPItemEventReceiverHandling();
    if (doNotFireEvents)
    {
        try
        {
            rh.DisableEventFiring();
            item.Update();
        }
        finally
        {
            rh.EnableEventFiring();
        }
    }
    else
    {
        item.Update();
    }
}

/// <summary>
/// Provides ability to update list item without firing event receiver.
/// </summary>
/// <param name="item"></param>
/// <param name="incrementListItemVersion"></param>
/// <param name="doNotFireEvents">Disables firing event receiver while updating item.</param>
public static void SystemUpdate(this SPListItem item, bool incrementListItemVersion, bool doNotFireEvents)
{
    SPItemEventReceiverHandling rh = new SPItemEventReceiverHandling();
    if (doNotFireEvents)
    {
        try
        {
            rh.DisableEventFiring();
            item.SystemUpdate(incrementListItemVersion);
        }
        finally
        {
            rh.EnableEventFiring();
        }
    }
    else
    {
        item.SystemUpdate(incrementListItemVersion);
    }
}

/// <summary>
/// Provides ability to update list item without firing event receiver.
/// </summary>
/// <param name="item"></param>
/// <param name="doNotFireEvents">Disables firing event receiver while updating item.</param>
public static void SystemUpdate(this SPListItem item, bool doNotFireEvents)
{
    SPItemEventReceiverHandling rh = new SPItemEventReceiverHandling();
    if (doNotFireEvents)
    {
        try
        {
            rh.DisableEventFiring();
            item.SystemUpdate();
        }
        finally
        {
            rh.EnableEventFiring();
        }
    }
    else
    {
        item.SystemUpdate();
    }
}

private class SPItemEventReceiverHandling : SPItemEventReceiver
{
    public SPItemEventReceiverHandling() { }

    new public void DisableEventFiring()
    {
        base.DisableEventFiring();
    }

    new public void EnableEventFiring()
    {
        base.EnableEventFiring();
    }


   }
}