https://examples.sencha.com/extjs/7....c#form-contact
Code:
app.js?_dc=1569255303876:1 Uncaught TypeError: Cannot read property 'firstNamefieldMargin' of undefined
    at d (app.js?_dc=1569255303876:1)
    at String.replace (<anonymous>)
    at ctor.processText (app.js?_dc=1569255303876:1)
    at ctor.renderCodeMarkup (app.js?_dc=1569255303876:1)
    at ctor.onComplete (app.js?_dc=1569255303876:1)
    at Object.callback (app.js?_dc=1569255303876:1)
    at ctor.onComplete (app.js?_dc=1569255303876:1)
    at ctor.onStateChange (app.js?_dc=1569255303876:1)
    at app.js?_dc=1569255303876:1
    at Object.elevate (app.js?_dc=1569255303876:1)