Unexpected Application Error!

Cannot read property 'h1' of undefined

TypeError: Cannot read property 'h1' of undefined
    at Vk (http://localhost:45678/static/js/main.302af837.js:2:826776)
    at ka (http://localhost:45678/static/js/main.302af837.js:2:319573)
    at kl (http://localhost:45678/static/js/main.302af837.js:2:376686)
    at xc (http://localhost:45678/static/js/main.302af837.js:2:365792)
    at yc (http://localhost:45678/static/js/main.302af837.js:2:365720)
    at vc (http://localhost:45678/static/js/main.302af837.js:2:365583)
    at ac (http://localhost:45678/static/js/main.302af837.js:2:362363)
    at ic (http://localhost:45678/static/js/main.302af837.js:2:360914)
    at S (http://localhost:45678/static/js/main.302af837.js:2:411197)
    at MessagePort.O (http://localhost:45678/static/js/main.302af837.js:2:411731)