The code says
L_Active = app.RelativeLigandConcentrationActivetoEC50EditField.Value;
but that component is called
app.RelativeLigandConcentrationtoActiveEC50EditField
note "Activeto" vs "toActive".
There are several other places where app properties and variables are misspelled in the code. I've fixed all the ones I found and attached a new version of the app.
It's a good idea to copy and paste the component name, rather than typing it all out manually, to decrease the chance of making a typing error, especially when the name is very long (and/or use shorter names).
