For our defense, there is several types of error, and some aren't attribuable to us :
* You have a black screen when you launch the updater You are in Custom Firmware 5.50 GEN-B, but not B-2. Update your CFW, and the problem will be resoled. * You have a semi-brick ("I just have the clock displayed...") You had a custom theme set and you had to format the flash1 via recovery menu. When you flash a console, one of the first rules is not to have a custom theme ... but nothing serious. If you can go to the recovery or if you reboot without memory card, it's good. * You bricked your console The installer of the CFW 5.50 GEN don't have any bug, and our CFW can't be directly responsible for that. Everything is working 200 %, you can be sure of that. Clearly, note that if you bricked your console, it's probably due to a failure of your nand which would occure at any other attempt of flash, including an official.
Note that GENyUS and Yoshihiro are currently working for fix this mistake, and they are going to release the Custom Firmware 5.50 GEN-D when everything will be validated and verified. It should not be long, and again, be sure that we are sorry for this panic.