showing error when I deployed my react app on Heroku, but working fine in my localhost

Uncaught TypeError: Super expression must either be null or a function
at index.js:974:1
at index.js:973:1
at Module.<anonymous> (index.js:972:1)
at n (index.js:14:1)
at e.exports (index.js:50:6)
at Object.<anonymous> (index.js:4:1)
at s ((index):1:1917)
at 92 (Navbar.js:67:10)
at s ((index):1:1917)
at 69 (main.68895b9e.chunk.js:1:171)