Hello! Something with is differing between XaAES and MagiC 6. XaAES have two shel_write extensions: #define SW_UID 0x1000 /* Set user id of launched child */ #define SW_GID 0x2000 /* Set group id of launched child */ The problem is that MagiC since version 6 have also a new extension: #define SHW_XMDFLAGS 4096 Gerhard