Click details on the crash report and look which thread crashed. If you find that some code in com.adobe.acrobat.pdfviewer is crashing, we may have solution for you:
The PDF viewer plugin from Adobe helps browsers to show the PDF content. But Safari and other browsers have such a viewer built-in, so the Adobe one is not needed. And the Adobe control is optimized to run within a browser and not the FileMaker application. We recommend to remove it and avoid those crashes. Your users probably won't miss it and your FileMaker solution is more stable.
Thread 38 Crashed:
0 libobjc.A.dylib 0x00007fff6cf3869d objc_msgSend + 29
1 com.adobe.acrobat.pdfviewer 0x000000011902faa3 0x119018000 + 96931
2 com.adobe.acrobat.pdfviewer 0x00000001190304d3 0x119018000 + 99539
3 com.adobe.acrobat.pdfviewer 0x000000011901a380 0x119018000 + 9088
4 com.adobe.acrobat.pdfviewer 0x000000011901a224 0x119018000 + 8740
Some clients even automate this by putting a line like this in the start script:
$r = MBS("Files.MoveToTrash"; "/Library/Internet Plug-Ins/AdobePDFViewer.plugin")
We've see such crashes with other development tools (e.g. Xojo) and embedded webkit controls before. Once you remove the Adobe PDF Viewer plugin, the default PDF viewer will kick in and show PDFs.