the simulation using expo won't start - react native
It might because the localhost is not defined with the required syntax in the "hosts" file of the system.
The file can be located @:
=> $ sudo nano /private/etc/hosts (iOS)
https://www.alphr.com/edit-hosts-file-mac-os-x/
=> etc/hosts
(above file for linux)
=> c:\ Windows \System32\Drivers\ etc \ hosts
(above file for Windows)
i.e. file has some wrong input.
So, Try replacing everything in that file with the text below as this is the default text that was always there in hosts file when it worked fine:
127.0.0.1 localhost
255.255.255.255 broadcasthost
::1 localhost
fe80::1%lo0 localhost
Source
https://github.com/expo/expo-cli/issues/1238