The worker for service class “(null)” cannot be instantiated.

When trying to upload an app to an ipad yesterday, I got the following message when trying to deploy:

The worker for service class “(null)” cannot be instantiated.

I’m running in XCode4, with Debugger options set to “None”.

By setting Debugger options to “GDB”, I was able to deploy to the device. I have no idea why this was happening.

Attempt to install on device fails due to restrictions

When attempting to install my app on an ipad, I was only able to run the app remotely. In other words, it wasn’t actually installing the app on the device, there was no “desktop” icon, and when I “stopped” the build, the app was killed on the ipad as well.

After wasting a bunch of time on this, I eventually realized that there were restrictions set up on the device so I couldn’t actually install my app (the debugger setting was a red herring, apparently). I removed those restrictions in the Settings menu:

General > Restrictions > Installing Apps > ON

and then I was able to install my app via XCode without any issues.