> For the complete documentation index, see [llms.txt](https://help.security.gallagher.com/knowledge-hub/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.security.gallagher.com/knowledge-hub/products/cloud-services/command-centre-mobile-client/troubleshoot/mobile-client-app-crashing-when-presen.md).

# Mobile Client app crashes when presenting a PIV card to iPhone

Resolve Mobile Client crashes caused by presenting a PIV card to an iPhone.

Presenting a PIV card on iPhone may crash the app. The app log shows **NFCError Code=100 "Stack Error"**, an Apple NFC internal bug.

**Resolution:** restart the phone. PIV cards work again afterward.

Expected app-log signature:

```
ERR  [CoreNFCCardReaderDevice]  got error Error Domain=NFCError Code=100 "Stack Error" UserInfo={NSLocalizedDescription=Stack Error, NSUnderlyingError=0x280545860 {Error Domain=nfcd Code=29 "Tag Error" UserInfo={NSLocalizedDescription=Tag Error}}}
ERR  [LookupCardReaderViewController]  Error Domain=NFCError Code=100 "Stack Error" ...
```


---

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