Software Failure 8000 0020
From Worms Knowledge Base
If Worms encounters a fatal error, for instance it runs out of memory, then it will issue the instruction TRAP #0, which should call an "trap handler" to deal with the problem. However, the game doesn't set up such a trap handler, so instead the standard OS trap handler is invoked - which crashes the computer and displays the message "Software Failure, Error: 8000 0020".
The freeware program WormsShell installs a trap handler which causes Worms to jump to its exit code if a fatal error occurs. This doesn't work perfectly as the game will still crash the machine on occasion.