but they should really tighten up their firmware release site as its a disgrace
In truth, the Hikvision Europe firmware download site is quite clear and well organised, in my view.
Downloads are grouped by the general type of device, and then by the model series of the device, with the firmware file names being clearly related to the model series as opposed to using a generic name.
There is even a cross-reference spreadsheet listing models against firmware.
I think that where you went wrong was not realising that the firmware release note that is included in all the download areas refers to the
firmware version number, the builds for which have been created for the ranges of models as specified in the release note.
So you can't pick just any part of the download area, look at the release note, and assume that the specific firmware in that download area will work for your model just because the release note says that the firmware version is available for your model.
I hope that makes sense, and is helpful for any future activity.