[HTC One A9] GuestK00271:
Ok first i flashed the firmware twice:

E:\Progs\Android\One A9\adb>htc_fastboot flash zip 2PQ9IMG_HIA_AERO_UHL_N70_SENSE80GP_MR_HTC_Europe_2.16.401.3_Radio_1.1.U40062.1@61209_60.00_F_release_492789_signed_Hboot_2_4.zip
htc_fastboot v3.0.9.2 (2015-05-29)
target reported max download size of 751200000 bytes
sending 'zip' (98847 KB)...
OKAY [ 4.655s]
writing 'zip'...
(bootloader) HOSD CL#853511
(bootloader) GPT (gpt_main_16g.img) is up-to-dated. [17408]
(bootloader) WARN Skip partition_info due to unmatched partition name
(bootloader) get 26 images from zip(zip_type=3)
(bootloader) start@26
(bootloader) apppreload.img@22%
(bootloader) apppreload.img@45%
(bootloader) apppreload.img@68%
(bootloader) apppreload.img@90%
(bootloader) apppreload.img@100%
(bootloader) aboot_signed.img@100%
(bootloader) cota.img@100%
(bootloader) dzdata_16g.img@100%
(bootloader) sbl1-8952-1.img@100%
(bootloader) hosd_signed.img@100%
(bootloader) rpm-8952-1.img@100%
(bootloader) boot_signed.img@100%
(bootloader) recovery_signed.img@100%
(bootloader) adsp.img@100%
(bootloader) dsp.img@100%
(bootloader) wcnss.img@100%
(bootloader) rcdata.img@100%
(bootloader) rfg_3.img@100%
(bootloader) modemst1.img@100%
(bootloader) modemst2.img@100%
(bootloader) fsc.img@100%
(bootloader) tz-8952-1.img@100%
(bootloader) hyp-8952-1.img@100%
(bootloader) cmnlib32.img@100%
(bootloader) keymaster.img@100%
(bootloader) pg2fs_ship_signkey.img@100%
(bootloader) splash1.nb0@100%
(bootloader) sensor_hub.img@BYPASS
(bootloader) radio.img@100%
(bootloader) tp_SYN3708.img@BYPASS
(bootloader) Update zip file OK
(bootloader) end@Done
OKAY [ 32.281s]
finished. total time: 36.936s
htc_fastboot finished. total time: 37.297s

After this step i immediately flashed the RUU (Without a reboot):

E:\Progs\Android\One A9\adb>htc_fastboot flash zip 2PQ9IMG_HIA_AERO_UHL_N70_SENSE80GP_MR_HTC_Europe_2.16.401.3_Radio_1.1.U40062.1@61209_60.00_F_release_492789_signed_2_4.zip
htc_fastboot v3.0.9.2 (2015-05-29)
target rom version: 2.16.401.3
found large-zip header, file count: 21
processing file 1/21...
sending 'zip' (98692 KB)...
OKAY [ 4.702s]
writing 'zip'...
(bootloader) HOSD CL#853511
(bootloader) GPT (gpt_main_16g.img) is up-to-dated. [17408]
(bootloader) Perform pre-update
(bootloader) WARN Skip partition_info due to unmatched partition name
(bootloader) WARN Skip backup_android-info.txt due to unmatched partitio
(bootloader) n name
(bootloader) get 25 images from zip(zip_type=3)
(bootloader) start@25
(bootloader) apppreload.img@BYPASS
(bootloader) aboot_signed.img@100%
(bootloader) cota.img@BYPASS
(bootloader) sbl1-8952-1.img@100%
(bootloader) hosd_signed.img@100%
(bootloader) rpm-8952-1.img@100%
(bootloader) boot_signed.img@BYPASS
(bootloader) recovery_signed.img@BYPASS
(bootloader) adsp.img@BYPASS
(bootloader) dsp.img@BYPASS
(bootloader) wcnss.img@BYPASS
(bootloader) rcdata.img@BYPASS
(bootloader) rfg_3.img@BYPASS
(bootloader) modemst1.img@BYPASS
(bootloader) modemst2.img@BYPASS
(bootloader) fsc.img@BYPASS
(bootloader) tz-8952-1.img@100%
(bootloader) hyp-8952-1.img@100%
(bootloader) cmnlib32.img@100%
(bootloader) keymaster.img@100%
(bootloader) pg2fs_ship_signkey.img@100%
(bootloader) sensor_hub.img@BYPASS
(bootloader) tp_SYN3708.img@BYPASS
(bootloader) splash1.nb0@BYPASS
(bootloader) radio.img@BYPASS
FAILED (remote: 90 hboot pre-update! please flush image again immediately )
finished. total time: 10.869s
preupdate done, rebooting...
resending command...
< waiting for device >
sending 'zip' (98692 KB)...
OKAY [ 5.668s]
writing 'zip'...
(bootloader) HOSD CL#853511
(bootloader) GPT (gpt_main_16g.img) is up-to-dated. [17408]
(bootloader) WARN Skip partition_info due to unmatched partition name
(bootloader) WARN Skip backup_android-info.txt due to unmatched partitio
(bootloader) n name
(bootloader) get 25 images from zip(zip_type=3)
(bootloader) start@25
(bootloader) apppreload.img@22%
(bootloader) apppreload.img@45%
(bootloader) apppreload.img@68%
(bootloader) apppreload.img@90%
(bootloader) apppreload.img@100%
(bootloader) aboot_signed.img@100%
(bootloader) cota.img@100%
(bootloader) sbl1-8952-1.img@100%
(bootloader) hosd_signed.img@100%
(bootloader) rpm-8952-1.img@100%
(bootloader) boot_signed.img@100%
(bootloader) recovery_signed.img@100%
(bootloader) adsp.img@100%
(bootloader) dsp.img@100%
(bootloader) wcnss.img@100%
(bootloader) rcdata.img@100%
(bootloader) rfg_3.img@100%
(bootloader) modemst1.img@100%
(bootloader) modemst2.img@100%
(bootloader) fsc.img@100%
(bootloader) tz-8952-1.img@100%
(bootloader) hyp-8952-1.img@100%
(bootloader) cmnlib32.img@100%
(bootloader) keymaster.img@100%
(bootloader) pg2fs_ship_signkey.img@100%
(bootloader) splash1.nb0@100%
(bootloader) sensor_hub.img@BYPASS
(bootloader) radio.img@100%
(bootloader) tp_SYN3708.img@BYPASS
(bootloader) Update zip file OK
(bootloader) end@Done
OKAY [ 26.700s]
finished. total time: 32.368s
processing file 2/21...
sending 'zip' (100510 KB)...
OKAY [ 4.801s]
writing 'zip'...
(bootloader) HOSD CL#853511
(bootloader) get 1 images from zip(zip_type=3)
(bootloader) start@1
(bootloader) system.img_00@43%
(bootloader) system.img_00@87%
(bootloader) system.img_00@100%
(bootloader) Update zip file OK
(bootloader) end@Done
OKAY [ 13.421s]
finished. total time: 18.222s
processing file 3/21...
sending 'zip' (97846 KB)...
OKAY [ 4.684s]
writing 'zip'...
(bootloader) HOSD CL#853511
(bootloader) get 1 images from zip(zip_type=3)
(bootloader) start@1
(bootloader) system.img_01@44%
(bootloader) system.img_01@88%
(bootloader) system.img_01@100%
(bootloader) Update zip file OK
(bootloader) end@Done
OKAY [ 10.527s]
finished. total time: 15.212s
processing file 4/21...
sending 'zip' (75010 KB)...
OKAY [ 3.822s]
writing 'zip'...
(bootloader) HOSD CL#853511
(bootloader) get 1 images from zip(zip_type=3)
(bootloader) start@1
(bootloader) system.img_02@44%
(bootloader) system.img_02@88%
(bootloader) system.img_02@100%
(bootloader) Update zip file OK
(bootloader) end@Done
OKAY [ 9.735s]
finished. total time: 13.557s
processing file 5/21...
sending 'zip' (67843 KB)...
OKAY [ 3.538s]
writing 'zip'...
(bootloader) HOSD CL#853511
(bootloader) get 1 images from zip(zip_type=3)
(bootloader) start@1
(bootloader) system.img_03@43%
(bootloader) system.img_03@87%
(bootloader) system.img_03@100%
(bootloader) Update zip file OK
(bootloader) end@Done
OKAY [ 10.177s]
finished. total time: 13.715s
processing file 6/21...
sending 'zip' (115052 KB)...
OKAY [ 5.317s]
writing 'zip'...
(bootloader) HOSD CL#853511
(bootloader) get 1 images from zip(zip_type=3)
(bootloader) start@1
(bootloader) system.img_04@43%
(bootloader) system.img_04@87%
(bootloader) system.img_04@100%
(bootloader) Update zip file OK
(bootloader) end@Done
OKAY [ 11.264s]
finished. total time: 16.581s
processing file 7/21...
sending 'zip' (90891 KB)...
OKAY [ 4.445s]
writing 'zip'...
(bootloader) HOSD CL#853511
(bootloader) get 1 images from zip(zip_type=3)
(bootloader) start@1
(bootloader) system.img_05@48%
(bootloader) system.img_05@96%
(bootloader) system.img_05@100%
(bootloader) Update zip file OK
(bootloader) end@Done
OKAY [ 9.857s]
finished. total time: 14.302s
processing file 8/21...
sending 'zip' (102755 KB)...
OKAY [ 4.851s]
writing 'zip'...
(bootloader) HOSD CL#853511
(bootloader) get 1 images from zip(zip_type=3)
(bootloader) start@1
(bootloader) system.img_06@46%
(bootloader) system.img_06@92%
(bootloader) system.img_06@100%
(bootloader) Update zip file OK
(bootloader) end@Done
OKAY [ 11.525s]
finished. total time: 16.376s
processing file 9/21...
sending 'zip' (62413 KB)...
OKAY [ 3.394s]
writing 'zip'...
(bootloader) HOSD CL#853511
(bootloader) get 1 images from zip(zip_type=3)
(bootloader) start@1
(bootloader) system.img_07@43%
(bootloader) system.img_07@87%
(bootloader) system.img_07@100%
(bootloader) Update zip file OK
(bootloader) end@Done
OKAY [ 9.358s]
finished. total time: 12.753s
processing file 10/21...
sending 'zip' (72377 KB)...
OKAY [ 3.707s]
writing 'zip'...
(bootloader) HOSD CL#853511
(bootloader) get 1 images from zip(zip_type=3)
(bootloader) start@1
(bootloader) system.img_08@43%
(bootloader) system.img_08@87%
(bootloader) system.img_08@100%
(bootloader) Update zip file OK
(bootloader) end@Done
OKAY [ 9.529s]
finished. total time: 13.236s
processing file 11/21...
sending 'zip' (60497 KB)...
OKAY [ 3.279s]
writing 'zip'...
(bootloader) HOSD CL#853511
(bootloader) get 1 images from zip(zip_type=3)
(bootloader) start@1
(bootloader) system.img_09@43%
(bootloader) system.img_09@87%
(bootloader) system.img_09@100%
(bootloader) Update zip file OK
(bootloader) end@Done
OKAY [ 9.220s]
finished. total time: 12.500s
processing file 12/21...
sending 'zip' (66752 KB)...
OKAY [ 3.492s]
writing 'zip'...
(bootloader) HOSD CL#853511
(bootloader) get 1 images from zip(zip_type=3)
(bootloader) start@1
(bootloader) system.img_10@44%
(bootloader) system.img_10@89%
(bootloader) system.img_10@100%
(bootloader) Update zip file OK
(bootloader) end@Done
OKAY [ 10.537s]
finished. total time: 14.029s
processing file 13/21...
sending 'zip' (85817 KB)...
OKAY [ 4.205s]
writing 'zip'...
(bootloader) HOSD CL#853511
(bootloader) get 1 images from zip(zip_type=3)
(bootloader) start@1
(bootloader) system.img_11@45%
(bootloader) system.img_11@91%
(bootloader) system.img_11@100%
(bootloader) Update zip file OK
(bootloader) end@Done
OKAY [ 9.812s]
finished. total time: 14.019s
processing file 14/21...
sending 'zip' (125659 KB)...
OKAY [ 5.690s]
writing 'zip'...
(bootloader) HOSD CL#853511
(bootloader) get 1 images from zip(zip_type=3)
(bootloader) start@1
(bootloader) system.img_12@44%
(bootloader) system.img_12@88%
(bootloader) system.img_12@100%
(bootloader) Update zip file OK
(bootloader) end@Done
OKAY [ 11.065s]
finished. total time: 16.755s
processing file 15/21...
sending 'zip' (93329 KB)...
OKAY [ 4.532s]
writing 'zip'...
(bootloader) HOSD CL#853511
(bootloader) get 1 images from zip(zip_type=3)
(bootloader) start@1
(bootloader) system.img_13@44%
(bootloader) system.img_13@88%
(bootloader) system.img_13@100%
(bootloader) Update zip file OK
(bootloader) end@Done
OKAY [ 10.283s]
finished. total time: 14.815s
processing file 16/21...
sending 'zip' (92606 KB)...
OKAY [ 4.514s]
writing 'zip'...
(bootloader) HOSD CL#853511
(bootloader) get 1 images from zip(zip_type=3)
(bootloader) start@1
(bootloader) system.img_14@44%
(bootloader) system.img_14@89%
(bootloader) system.img_14@100%
(bootloader) Update zip file OK
(bootloader) end@Done
OKAY [ 10.917s]
finished. total time: 15.431s
processing file 17/21...
sending 'zip' (84807 KB)...
OKAY [ 4.193s]
writing 'zip'...
(bootloader) HOSD CL#853511
(bootloader) get 1 images from zip(zip_type=3)
(bootloader) start@1
(bootloader) system.img_15@45%
(bootloader) system.img_15@90%
(bootloader) system.img_15@100%
(bootloader) Update zip file OK
(bootloader) end@Done
OKAY [ 9.866s]
finished. total time: 14.059s
processing file 18/21...
sending 'zip' (89236 KB)...
OKAY [ 4.340s]
writing 'zip'...
(bootloader) HOSD CL#853511
(bootloader) get 1 images from zip(zip_type=3)
(bootloader) start@1
(bootloader) system.img_16@44%
(bootloader) system.img_16@88%
(bootloader) system.img_16@100%
(bootloader) Update zip file OK
(bootloader) end@Done
OKAY [ 10.217s]
finished. total time: 14.558s
processing file 19/21...
sending 'zip' (82877 KB)...
OKAY [ 4.102s]
writing 'zip'...
(bootloader) HOSD CL#853511
(bootloader) get 1 images from zip(zip_type=3)
(bootloader) start@1
(bootloader) system.img_17@43%
(bootloader) system.img_17@87%
(bootloader) system.img_17@100%
(bootloader) Update zip file OK
(bootloader) end@Done
OKAY [ 10.663s]
finished. total time: 14.767s
processing file 20/21...
sending 'zip' (55497 KB)...
OKAY [ 3.077s]
writing 'zip'...
(bootloader) HOSD CL#853511
(bootloader) get 1 images from zip(zip_type=3)
(bootloader) start@1
(bootloader) system.img_18@99%
(bootloader) system.img_18@100%
(bootloader) Update zip file OK
(bootloader) end@Done
OKAY [ 6.430s]
finished. total time: 9.507s
processing file 21/21...
sending 'zip' (15960 KB)...
OKAY [ 1.610s]
writing 'zip'...
(bootloader) HOSD CL#853511
(bootloader) get 2 images from zip(zip_type=3)
(bootloader) start@2
(bootloader) dzdata_16g.img@100%
(bootloader) boot_signed.img@100%
(bootloader) Update zip file OK
(bootloader) end@Done
OKAY [ 5.783s]
finished. total time: 7.393s
rompack updated
htc_fastboot finished. total time: 344.939s

And it looks like it worked after a long boot process, it started with the, think it's called device assistent. Now i am downloading my apps and everything looks good.

Thank you scotty2000 :)