Be sure to always explain what the actual problem is that you're experiencing.
If this is a crash in the PDF reader on iOS, can you reproduce it reliably? Does it happen with a specific PDF? If so, send the PDF to support@zotero.org with a link to this thread, and post the exact steps to reproduce here.
If this is a crash in the PDF reader on iOS, can you reproduce it reliably? Does it happen with a specific PDF? If so, send the PDF to support@zotero.org with a link to this thread, and post the exact steps to reproduce here.