Just got out of this myself
please help,
safestrap said "NO OS INSTALLED". i dont know why, i wipe date, dalvik, system. and trying to install

but after i reboot my phone, just only see black screen.
I had this issue, I was trying to flash stock slot, the issue was it kept failing to load the system, as it for some reason said 0 MB.
Anyways You should be able to flash to one of your other slots, but to fix this, what I did was I used Dr....*he who shall not be named*'s files which were for getting to safe strap in odin.
So Put your phone into download mode, Open up odin Flash the AP and BL file. Then it will restart and it should give you access to the stock slot and allow you to install on the stock slot.
If you are having issues with this I would suggest create a new slot flash a KK Rom on this for the time being until you have some time to really dig in.
By the way, I wiped my SD Card figuring this out. maybe you should take it out just in case

Good luck:silly: