The app runs great from XCode, no errors.
I make an archive. I make an ad-hoc build, run the IPA, no errors.
I use the same archive to upload to the app store. It crashes on GameCenter login. The report is in the image below. (String_Concat_m2596509543)
Any ideas what may be going on here?
Additional info: on the first release of the app, I forgot to enable GameCenter Capabilities (it used to be on by default). It ran fine from XCode, but the ad-hoc IPA crashed. In this version, it is enabled, and the IPA works.