Exception in rendering!

Message: Cannot read property 'h1' of undefined

TypeError: Cannot read property 'h1' of undefined
    at r.L.value (<eval>:217:509889)
    at o (<eval>:143:11774)
    at we (<eval>:143:12048)
    at e.t.render (<eval>:143:14564)
    at e.t.read (<eval>:143:14140)
    at _e.renderToString (<eval>:143:19346)
    at f.a.register.App (<eval>:217:1105584)
    at t.default (<eval>:73:515668)
    at t.default (<eval>:143:25286)
    at Object.g.ReactOnRails.serverRenderReactComponent (<eval>:73:2803)