Crashes on systems using MultiUserFileSystem
From Worms Knowledge Base
Every call Worms makes to the DOS function Lock(), apart from those in the Blitz library functions, specifies the lock type as 0 instead of SHARED_LOCK, which it should be. The standard Amiga file system doesn't mind this but, for security, MultiUserFileSystem does. This means that the Lock() call fails and Worms thinks files are not there.
No official fix for this glitch was ever released, however WormsShell fixes these calls to use SHARED_LOCK.