Can't flash OTA file using TeamWin Recovery on HTC One
There's a "file integrity check" involved with the flash process, to prevent broken/tampered files from being flashed. Basically, you've got 3 options:


Get the .md5 file that should go along the .zip
generate the .md5 yourself (if you cannot find it, and are sure your .zip is fine)
Turning off verification in TWRP.


Btw: There was a discussion at AndroidCentral on this topic, which you might wish to check.