![javascript - keep getting "? Something is already running on port 3000" when I do npm start on react app - Stack Overflow javascript - keep getting "? Something is already running on port 3000" when I do npm start on react app - Stack Overflow](https://i.stack.imgur.com/RfGE1.png)
javascript - keep getting "? Something is already running on port 3000" when I do npm start on react app - Stack Overflow
![Why puma workers constantly hung, and how we fixed by discovering the bug of Ruby v2.5.8 and v2.6.6 | by Yohei Yoshimuta | ITNEXT Why puma workers constantly hung, and how we fixed by discovering the bug of Ruby v2.5.8 and v2.6.6 | by Yohei Yoshimuta | ITNEXT](https://miro.medium.com/max/1400/1*kJlineY1h8TLUJ9L8pLceA.png)
Why puma workers constantly hung, and how we fixed by discovering the bug of Ruby v2.5.8 and v2.6.6 | by Yohei Yoshimuta | ITNEXT
There is already a server bound to: /var/run/puma/puma.sock (after OS + ruby upgrade) · Issue #2638 · puma/puma · GitHub
![javascript - keep getting "? Something is already running on port 3000" when I do npm start on react app - Stack Overflow javascript - keep getting "? Something is already running on port 3000" when I do npm start on react app - Stack Overflow](https://i.stack.imgur.com/nsITN.png)