The template "crashsig" does not exist or has no approved revision. js_TraceObject
Mozilla developers are aware that this is a common Firefox crash, but haven't figured out what causes it. If you want to help, you can provide more information on the bug report.
The general crash troubleshooting steps have steps that may help with this crash. You can also try providing a few crash IDs when you ask a question in case there is useful information in the crash report that isn't in the crash signature.