this.context.router is undefined in ES6 class constructor · Issue #1059 · remix-run/react-router · GitHub
TypeError: 'undefined' is not an object (evaluating 'this.context.router.history.createHref') · Issue #5834 · remix-run/react-router · GitHub
![reactjs - react-router throwing TypeError: useContext(...) is undefined when using useHistory - Stack Overflow reactjs - react-router throwing TypeError: useContext(...) is undefined when using useHistory - Stack Overflow](https://i.stack.imgur.com/QKwdZ.png)
reactjs - react-router throwing TypeError: useContext(...) is undefined when using useHistory - Stack Overflow
![TypeError: Cannot read property 'fields' of undefined after migrating from v5 to v8 on forest-express ResourceSerializer when getting fields names - Help me! - Forest Admin Developers Community TypeError: Cannot read property 'fields' of undefined after migrating from v5 to v8 on forest-express ResourceSerializer when getting fields names - Help me! - Forest Admin Developers Community](https://europe1.discourse-cdn.com/business20/uploads/forest/original/2X/6/6106ba4e1f0d7b9f1571081fad2a1342f895b441.png)