Add to Cache error

I have a user who has been getting a couple of errors on his E1 sessions which require him to log off/on several times a day.

The first error occurs when he deletes a work order and then tries to edit the quantity or date on a second work order.  When he tries to save the second work order, he receives an error "Add to cache X4801-5703 failed".  The error is on Form P48013-W48013A on OK Button Clicked line 229.

The second error occurs when he closes a work order's routing or when he browses an item's supply and demand screen.  He receives a Web Client Exception screen.  An example is below.