On some OS X installations ZINC Builder crashes when it loads flash movie used to be source for native application content and then renders it in preview section.
The crash occurs after 10.1.53.64 version of Flash runtime is installed on local machine but only if end-consumer (non-debugger) version of that runtime is installed and used (ZINC Builder tries to use local/system version of Flash runtime to render preview of flash content by default).

To work around issue:
#1
do not use preview feature (toggle off its toolbar button)
or:
#2
download debugger version of Flash 10.1.53.64 runtime from Adobe's distribution page:
http://www.adobe.com/support/flashplayer/downloads.html

Part of crash report log:
Exception Type: EXC_BAD_ACCESS (SIGBUS)
Exception Codes: KERN_PROTECTION_FAILURE at 0x0000000000000000
Crashed Thread: 0 Dispatch queue: com.apple.main-thread

Thread 0 Crashed: Dispatch queue: com.apple.main-thread
0 ??? 0000000000 0 + 0
1 com.apple.WebKit 0x95cf15df -[WebNetscapePluginPackage
_tryLoad] + 879
2 com.apple.WebKit 0x95cf1207 -[WebNetscapePluginPackage
load] + 39
3 com.apple.WebKit 0x95d3d30f
-[WebNetscapePluginDocumentView
initWithFrame:pluginPackage:URL:baseURL:MIMEType:attributeKeys:attributeValues:loadManually:element:]
+ 335