DTAssetProviderService could not start DTXConnection with Simulator

Question

After updating to Xcode 7.3 I am not able to run my app in the iOS Simulator.

On every attempt I am getting the following error message:

DTAssetProviderService could not start DTXConnection with Simulator 'iPhone …'. Check the system log for errors.

I have checked the following Apple developer forums thread but didn't any provide any solution. Suddenly when I have cleaned & deleted the old app from the simulator and rebuilt, it works fine. This issue was not only for the first time.

Can anybody explain this issue in detail?

Mar 24 10:18:38 CoreSimulatorService[521] : com.apple.CoreSimulator.CoreSimulatorService 209.19 starting.
Mar 24 10:18:44 CoreSimulatorService[521] : Requested watch is is not available for pairing. Assuming it has the capability.
Mar 24 10:18:44 CoreSimulatorService[521] : Requested phone is is not available for pairing. Assuming it has the capability.
Mar 24 10:18:44 CoreSimulatorService[521] : Requested watch is is not available for pairing. Assuming it has the capability.
Mar 24 10:18:44 CoreSimulatorService[521] : Requested phone is is not available for pairing. Assuming it has the capability.
Mar 24 10:18:45 com.apple.dt.Xcode[455] : Requested watch is is not available for pairing. Assuming it has the capability.
Mar 24 10:18:45 com.apple.dt.Xcode[455] : Requested phone is is not available for pairing. Assuming it has the capability.
Mar 24 10:18:45 com.apple.dt.Xcode[455] : Requested watch is is not available for pairing. Assuming it has the capability.
Mar 24 10:18:45 com.apple.dt.Xcode[455] : Requested phone is is not available for pairing. Assuming it has the capability.
Mar 24 11:02:29 com.apple.iphonesimulator[712] : Requested watch is is not available for pairing. Assuming it has the capability.
Mar 24 11:02:29 com.apple.iphonesimulator[712] : Requested phone is is not available for pairing. Assuming it has the capability.
Mar 24 11:02:29 com.apple.iphonesimulator[712] : Requested watch is is not available for pairing. Assuming it has the capability.
Mar 24 11:02:29 com.apple.iphonesimulator[712] : Requested phone is is not available for pairing. Assuming it has the capability. Mar 24 11:02:31 CoreSimulatorService[521] : Could not register service com.apple.coreservices.lsuseractivity.simulatorsupport: Failed to lookup com.apple.coreservices.lsuseractivity.simulatorsupport: 0x44e

My guess for this issue: I am not sure but my guess is when I updated Xcode, the iOS version updated to 9.3 but the app was already installed in the iPhone 6 Plus simulator when the old version (9.2) was installed. Therefore when I tried to run the app with iOS 9.3 I was configured for iOS 9.2 only, and due to incompatibility it crashed.

Ignore

The dialog indicates that you should check the system log for errors. Please add those errors to your question as well as any errors in ~/Library/Logs/CoreSimulator/CoreSimulator.log – Bucko

Nobody is going to be able to help out if you cannot provide the relevant data. Can you provide relevant snippets from /var/log/system.log and ~/Library/Logs/CoreSimulator/CoreSimulator.log around the time of the failure. If not, can you host the entire files, so I can comb through them. – Bucko

@JeremyHuddlestonSequoia, pardon me for the delay. I have attached log snippet in my question. Suddenly it's working, just cleaned the project build. But didn't get the exact solution for this problem. – Ignore

Those log messages aren't relevant to the issue here. – Bucko

Based on some other messages here and in the dev forums, my current hunch is that this may be something timing out on the first boot of a device. Does it only happen the first time? What type of disk do you have (HDD or SSD)? Anything interesting in /var/log/system.log from Xcode around the time of the issue? Anything interesting in ~/Library/Logs/CoreSimulator/<Device UDID>/system.log? – Bucko

It works. Just quit xcode and restart again. no need to quit simulator in my case – Hamhung

@JeremyHuddlestonSequoia i've updated the thread on the apple forums with more info/logs/etc forums.developer.apple.com/message/133995#133995 – Acis

Getting same error on macOS Sierra with Xcode 7.3 – Biquadrate

@KiritVaghela Use Xcode 8 beta to Xcode 7.3.1 .dmg downloaded from the Mac Developer portal for a fix developer.apple.com/download/more – Simonides

Answer 1

Killing the simulator and restarting it from Xcode helped me.

You are probably using macOS Sierra which breaks Xcode 7.3.1 (mac store version)

Use Xcode 8 beta or Xcode 7.3.1.dmg downloaded from the Mac Developer portal for a fix https://developer.apple.com/downloads

Direct link to Xcode 7.3.1: http://adcdownload.apple.com/Developer_Tools/Xcode_7.3.1/Xcode_7.3.1.dmg

Hetzel

Likely not actually the solution, but it may indicate that "something" might be waiting for DataMigration to complete and timing out. The next time you tried, DM didn't need to run, so it may have not timed out. Do you have an HDD or SSD? – Bucko

I have a HDD. Agree that it probably is a time out issue. I am on a slow machine. – Hetzel

I can't find that download on Apple downloads (more downloads) page. Has it been removed? – Kendrakendrah

@Kendrakendrah - I have edited the answer to add a direct link to the download. – Hematite

@MatthewCawley Thanks Matthew. So the link was just the good ol Xcode. I thought it was any kind of tool to reverse the problem. I'll try this Xcode 7 version then since I have the MAS version installed. Thanks – Kendrakendrah

This version worked on mine. Not sure what is different between the AppStore version, maybe they patched a file to make it work in Sierra. – Hematite

It seems that the your direct link doesn't work. I kept getting "unauthorized" even though I was authenticated. I found the download here: developer.apple.com/download/more – Boles

Answer 2

Yes,It happens after upgrading to Xcode 7.3 and Probably You run first time in a simulator.

When you see this error, Just click "Ok" but Don't quit Simulator or Xcode,Simulator will continue with its process and you can see the progress bar. Let it finish first and then Run project again,You will able to make it run successfully.

Hymettus

I upgraded from El Captian + Xcode 8 to Seirra + Xcode 8.2.1. And I'm facing this issue. I also had Xcode 7 installed from before...deleted that as well. still doing what you suggest doesn't work...no progress or anything... – Elimination

Answer 3

I quit my Xcode and Simulator then opened my project and ran again, it worked for me. But I dont understand what kind of error and why it occured.

Rossanarosse

Answer 4

1. Exit both Xcode and simulator
2. Delete Derived data [Right click on finder and select "Go To Folder" Type ~/Library/Developer/Xcode/DerivedData/ in textbox. it will redirect you to DerivedData folder.
3. Delete all folders inside it.
4. Relaunch Xcode and Run your project again.

your issue will be solved.

Mordred

I don't know why you were down voted but your answer is the only one that solved the issue. THANKS. – Grout

Answer 5

Can't believe for me it's solved by just restarting mac :O

Arola

Answer 6

Yes,It happens after upgrading to Xcode 7.3 and Probably when you run your project first time in a simulator.

Following are the solution 1) Try to reset the simulator 2) Terminate / Kill the simulator 3) Terminate / Kill the Xcode and run again.

Hope any of above 3 helps you.

Arriviste

Answer 7

Simply delete the old App from the simulator by going to: Hardware -> Home (Here, you will be returned to the home screen of the simulator). Now press and hold the old app icon on the simulated 'home' screen until all the apps start wobbling. Tap the cross and you will be asked to confirm the deletion.

Now build your app again and all should be fine.

School

Answer 8

For me, it was an issue with having WebSense installed by my IT department. It is known to inject libraries into other processes such as Simulator. Once removed, it was working again.

Rabbitry

Answer 9

For me quiting Xcode & Simulator(Reset) and restarting Mac Resolved.

Zwiebel