error: can't allocate region

```
$ ./RepeatScout -sequence Ca_dromedarius_kacst.fna -output output_repeats -freq output -l 14
RepeatScout(9531,0x7fff9faf2380) malloc: *** mach_vm_map(size=18446744073479073792) failed (error code=3)
*** error: can't allocate region
*** set a breakpoint in malloc_error_break to debug
Could not allocate space for sequence
```


any idea how to solve the issue 