Problem installing Firmware Copter 3.6 on ArduCopter APM 2.8

Hello, I am a student currently doing my Bachelor Thesis, and I have to build a drone.
Unfortunately, I can’t install the Firmware Copter 3.6 on my ArduCopter 2.8 Flight Controller through Mission Planner. I tried with APM Planner but same problem.
Thank you for your comprehension

Regards

Adrien

So you know what a Wiki is.

If you read it, you will learn that latest Arducopter for APM is 3.2.1 version Feb 2015.

http://ardupilot.org/copter/docs/common-apm25-and-26-overview.html#archived-apm-2-5-and-2-6-overview

To be a bit more polite in a response, the ArduPilot Project hasn’t supported the old 8 bit hardware for what must be approaching 5 years. By using one you miss out on all the development that has taken place since 3.2.1, which is a massive amount.
Whilst some retailers insist on selling them, we don’t support them.
The list of supported autopilots is here:
http://ardupilot.org/copter/docs/common-autopilots.html

You are right to be polite, but a student facing a problem, should have some problem solving strategies and 5 sec with google and the search term “apm 2.8 arducopter 3.6” leads to the answer in the first search result…