0065: External script label not found
Possible solutions: make sure that each external script declared in the header exists in the source file. Either add a missed script, or remove the declaration:
DEFINE MISSIONS 1
DEFINE MISSION 0 AT @MISSION_0
DEFINE EXTERNAL_SCRIPTS 2
DEFINE SCRIPT TEST AT @SCRIPT
DEFINE SCRIPT TEST2 AT @SCRIPT2
DEFINE UNKNOWN_EMPTY_SEGMENT 0
DEFINE UNKNOWN_THREADS_MEMORY 0
:MAIN
:MISSION_0
:SCRIPT
// error, SCRIPT2 not found