If you are getting a random number (-2.15E+09) on your scales or when you load a sheet it occasionally works but sometimes crashes, you will need to check that the scale cells don’t have a error equation. Examples would be results giving an NA.
To fix this you will need to make sure that the cells which are controlling the scales don’t have an equation resulting in and excel error. This may require some testing as it will be one of the conditions and with complex equations its not always obverse.
Simple solution not put any complex equation into the scale cells.