Locating crash logs:
The crash error pop-up should tell you where the crash log has been written to. Most often it will be in your home directory under AppData. Ensure you select "Hidden Items" under the View menu in your file browser.
On OSX crash logs are saved in /tmp. You can only see this directory through a Terminal (Utilities->Terminal), not through the interface.
On Linux, the crash logs are saved in /tmp/houdini_temp