I guess you're here because you've updated to 4.3 and lost the root access to your HTC One. This is simple to fix, just follow below instructions.

• Download UPDATE-SuperSU-v1.65.zip from http://www.androidfilehost.com/?fid=23134718111254559.
• Place the downloaded zip into: Computer\HTC One\Internal storage on your HTC One.
• Now by holding volume down key and going to recovery mode, login to TWRP which must be already installed on your HTC One device. - - Once in TWRP, go to Install, browse to internal storage and select and run: UPDATE-SuperSU-v1.65.zip
• You're done, your root is back.