Cannot run a macOS app developed on one computer on another computer

Please HELP!!


I am a newbie to macOS and XCode programming/development. I am trying to create an app for a co-worker to be able to read information from files generated by a device made by my company.


I put together the app, and I can build it and run it from Xcode just fine.


I then figured out from digging around online that I could just take the .app file under the products tab and run it as a stand alone application (note: I don't have a paid developer account). This seemed to work just fine. I work across a desktop and a laptop, and I was able to build the program on my desktop and run it in my laptop.


I then proceeded to make some changes/improvements to the program (mostly dealing with Date objects), and now I can only run the .app on the machine that I build it on. If I build it on one machine and try opening it on the other machine, now I get an error that says 'The application "myApp" can't be opened.'


If I try building the app on the second machine (all code synced via cloud) without first cleaning it, I get the error message 'dyld: Library not loaded: @rpath/libswiftAppKit.dylib' with additional information that indicates where it is looking, says 'no suitable image found' and says it did find a file, but the code signature was invalid.


I'm trying to do this without paying th $100 developer fee, since it is just for me to hand over to my co-worker for his use.


If it helps at all, I'm running Xcode 8.3.3 under macOS sierra.


Any help would be greatly appreciated!!! Thanks!