Xcode signing problems with iphone app: is it possible to build and run without signature?

Question

Not the most bright question, but I really need an answer.

I created an iPhone app with a friend. I did the first 100 hours of the development (by myself) and he did the rest (sometimes I'd help him debug in class). He then took it over completely; finished it and uploaded it to the app store (no idea how that process works). Since we don't know git well enough I emailed him the code. A few days ago I asked him the most recent version of the code back, so he mailed it to me in a zip file and now I can't build the app.

What I want to do is build and run the app in the simulator.

Instead I get the following error:

Even the play button doesn't display anything.

My friend also has no idea why this error occurs. My guess is that he barely knew enough to upload everything to the app store. Also I don't have a developer account, because the person who we are building this app for has it. He gave it to my friend, but my friend doesn't want to give it to me. And the person who has the developer account is not responding.

What should I do? I "just" want to build and run it on my macbook (I know, it probably isn't that easy).

What do I need to know?

Answer 1

So my target was the following at first. This was my only option. Clicking at it did not help, it only showed this thing as an option.

Then after the comment of Nitin I poked around for a bit (for the 10000th time). I did this by clicking on the gear icon which has the option "Manage Schemes..."

I don't know what a scheme is and I remembered that I never saw this menu box before. For fun I clicked on "Autocreate Schemes Now". I got this as a result.

My guess is that it was a new target to build at, and indeed it was.

I can now build and run my project without signing.

Thanks for the comment, it led me to the answer while clicking around once again :)