Rickin: Hi, thank you for contacting Samsung Technical Support. How may I help you today?
Rickin: Not to rush you, are we still connected on the chat?
Visitor: Hi, i have a Galaxy S5 SM-900F. There is KNOX warranty (in download mode) at 0x1. I have thewarranty?
Rickin: I understand that you are facing issues with KNOX application, is that correct?
Visitor: yes
Rickin: May I know the model number of your phone? You can find the model number beneath the phone's battery which generally starts with GT, SM, SGH, SCH or SPH. You can also find it from device home screen app >> Settings >> About Device >> Model number.
Rickin: Ignore the step.
Visitor: i want know if with KNOX at 0X1 there is the Warranty
Rickin: Let me check, I will provide you with the required information.
Visitor: SM-G900F
Rickin: Thank you for providing the model number.
Visitor: if knox is altered at 0x1...I am covered by warranty ?
Rickin: Thank you waiting.
Rickin: I have checked the information, when the KNOX reaches 1x1. It would void the warranty provided by Samsung.
Visitor: my knox is 0x1.. not 1x1
Rickin: Yes, then it would be covered under warranty.
Visitor: when i have purchased my Galaxy S5, KNOX is 0x0, now is 0x1
Rickin: If it reaches 1x1 it would the warranty, so there is no issues with the warranty status of you device.
Rickin: It would be covered under warranty.
Visitor: Thank you... and if the device is rooted?
Rickin: Then also the device voids the terms of warranty if the device is rooted.
Visitor: okay
Rickin: You're welcome. Is there anything else I can assist you with?
Visitor: if i want reset knox at 0x0?
Rickin: There are no options to revert it.
Rickin: It depends on how many times you root the device.
Visitor: and you how fix this?
Rickin: The KNOX alters to 0x1 as its rooted once, if you root the device once more it would come under out of warranty device.
Visitor: ok, thank you!
Rickin: You're welcome. Is there anything else I can assist you with?
Visitor: no no thank you.... good night

Rickin: As of know there are no such options available, I will surely share your feedback with appropriate department.