In a statement, the Taiwanese manufacturer said it was "temporarily suspending" the update due to the unspecified problems being experienced by users.
Some who have already downloaded the update are complaining of poor battery life, but it is unclear whether this is the extent of the difficulties.
The company told Android Central: "We are aware that a limited number of HTC users are experiencing difficulties with the KitKat update.
"As a result, all FOTA updates have been temporarily suspended. HTC is committed to providing customers with the best possible mobile experience and we are working hard to resolve the issue quickly."
The UK was not among the first wave of European countries to receive the update in January and the company only announced the KitKat for British HTC One owners last week.