How can I activate the device administrator for the default email app on a Samsung S5?

A

AC Question

How can I activate the device administrator for the default email app on a samsung S5

This is for a samsung SM-G901F, it runs android 4.4.4, kernel 3.10.0-2413392
Everything worked perfectly fine since I bought this phone in december 2014.

Since around june 15, I keep getting a prompt telling me that a microsoft exchange account need an update of its security settings.
I also have an hotmail account under activ sync that works perfeclty fine.

After pressing ok, I recieve another prompt to activate the device administrator, when I accept and press activate, the window shut itself as if it was ok. Immediatly after that, I get a notification for the frist prompt, back to te begining.
So I'm sort of stuck into a loop.

I have checked on the server, my phone is activated and authorised to access the server.

I have tried to reset the security policies + power off and no battery for 60 seconds.
I have tried to erase all accounts and email data and to set it up again.
I have tried to change and add any combination of pin/password for the lockscreen and for a startup prompt.
I have tried to manualy active the device administrator in the security setting, but there is nothing there except the geolocating service.

So I am short of ideas and don't seem to find this particular problem anywhere else.

Any input is welcomed