Xcode process launch failed: invalid host string: '(null)'

Question

I am trying to learn Objective C. However, when I write some code and run it, xcode says build sucsessful but the code does not run. Eventually it comes up saying:

process launch failed: invalid host string: '(null)'

Please help.

I have also already reinstalled it.

Answer 1

Xcode error Invalid string localhost

open terminal and type

sudo nano /etc/hosts

If it asks for password ,enter password;

copy and paste this commands

127.0.0.1       localhost
255.255.255.255 broadcasthost
::1             localhost 
fe80::1%lo0     localhost

then press

control-o

and then press

enter

and then press

control-x

then type

  dscacheutil -flushcache 

Thats it !!!!

Answer 2

I've encountered this couple times and what I did to overcome this are such as:

• Reconnect the cable between Macbook and target device
• Uninstall the app and re-install it

Note that it happened on my old iPhone especially. You should try tinkering around something like above first to make sure that you don't overlook what might be simple solution.

Answer 3

make sure that your signing in with developer profile not distribution in your build setting provisioning profile.

hope it helps.