Can't boot into recovery

Hi,

I flashed several recoveries on my S5.
When I try to boot into the recovery (either with VolUp+Home+Power or with adb reboot recovery),
on the top left corner 3 lines are show with:

RECOVERY BOOTING
Recovery is NOT SEANDROID ENFORCING
Set Warrenty Bit : recovery

and the logo.
After 5-10 seconds it continues to a black screen and I have to disconnect the usb cable and the batterie to turn it of.

I tried This but it didn't help.
The option mentioned in This video was also disabled.

I tried the following recoveries, non of them worked, all with the same error as above, some of them even throw me right back into download mode:
CF-Auto-Root-hlte-hltexx-smn9005.tar
CF-Auto-Root-klte-kltexx-smg900f
CF-Auto-Root-klte-kltedx-smg900f
openrecovery-twrp-2.8.5.0-gt-klte
openrecovery-twrp-2.8.4.0-klte
openrecovery-twrp-2.8.1.0-klte
k3gxx
philz_touch_6.57.8-klte.tar
openrecovery-twrp-2.7.0.0-klte
philz_touch_6.26.2-klte.tar

As for my OS, it's stock with the following details:
Modellnr: SM-G900F
Android-Version: 5.0
Basisbandversion: G900FXXU1BOE5
Kernel-Version: 3.4.0-4920185
dpi@SWDD6122 #1
Buildnumber: LRX21T.G900FXXU1BOE5
SE for Android Status:
Enforcing
SEPF_SM-G900F_5.0_0027
KNOX-Version:
KNOX 2.3

Thank you in advance