Exception in rendering!

Message: Cannot read property 'slug' of null

TypeError: Cannot read property 'slug' of null
    at new t (<eval>:80:356102)
    at v (<eval>:67:10277)
    at e.render (<eval>:75:6848)
    at e.read (<eval>:75:6594)
    at re.renderToString (<eval>:75:9776)
    at t.default (<eval>:75:20787)
    at r (<eval>:46:20159)
    at o (<eval>:75:18557)
    at Object.k.ReactOnRails.serverRenderReactComponent (<eval>:51:41864)
    at <eval>:11:23