For some reason, when I set over 9 intensity it's crashing. From what I've read in this thread, people trying to run over 9 cards have a problem too. So what I understand it that any 2-digit numbers is causing a crush.
Was an answer provided and I missed it?

For what GPU type are you trying to change intensity? You don't need to change it for GTX 1070 as it's already fine tuned and you can't randomly change it because algo optimized for certain value. Also, 9 is very low value, why do you specify it? Lowest default intensity for slowest card (GT 1030 and alike) is 15.
2-digit numbers doesn't cause crash. It was bug in original hsrminer and I've already fixed it:
- Fixed bug of original hsrminer - now you can use GPU's numbers > 9 with -d option, i.e. -d 10,11,12