Xcode 8 | iOS 10 simulator "Error returned in reply: Connection invalid"

While I am try to run an app in the iOS 10 simulator using xcode8 I get these alerts frequently. They randomly appear two at a time and it is not apparent what is triggering them.

Below is Image for Error I got.

I tried Following things.

• Clean & Rebuild an app
• Restart xcode & Simulator
• Clear Derived Data & Rebuild application.

Solution 1:

Even I was getting the same error. Issue in my case was I was working on xcode 7.3 and its simulator was open, later on I closed xcode 7 and opened xcode 8 and tried running app and got the above error.

I guess its happening because of both the simulator were open, it got solved when I closed my older simulator. Seem to be some problem while xcode 8 was trying to establish connection with simulator.

Solution 2:

You just follow these steps to remove this error it's working fine in my side and i hope these steps work to you also just try it.

 i)Remove multiple xcode versions.
ii)Quit all Xcode and simulators. 
iii)Only one version you opened.
iv)Go to Xcode  -> Preferences

v)Go to Location vi) Set proper version for command line tools (your Xcode version)

vii)click on Derived Data

viii)Then go to Derived data and delete that folder. see below image

ix) Click on Simulator reset content settings and just quit xcode and simulator and open clear and build the xcode and run it.