Mac iCamSource crash logs are usually more informative than Windows ones, unfortunately.
These days, Mac iCamSource crashes are usually due to an old 3ivx codec being installed (uninstalling the codec fixes the issue) or excessive CPU usage. Windows iCamSource crashses are usually due to invalid / corrupt iCamSource settings or excessive CPU usage.
If the iCamSource crashes or disappears when it is first launched or when the Start button is clicked, deleting the com.skjm.icamsource.plist file in your Library/Preferences folder (Mac) or downloading and running the
http://skjm.com/icam/CleaniCamKey.reg registry cleaner (Windows) will reset your iCamSource settings and should allow you to launch the iCamSource again.
If the iCamSource crashes or disappears sporadically after running for a while, it is likely an excessive CPU usage issue. To reduce the CPU usage of the iCamSource, try reducing the overall number of cameras, or in the case of network IP cameras, reducing the MJPEG frame rate of each camera to around 2-5 frames per second. You can also try closing (hiding) the iCamSource Preferences window and/or disabling Motion Detection to reduce the CPU usage of the iCamSource and see if that improves its stability.