G901F flash odin fail

Hi, so this is my first flash.. my phone came with Android 5.0.2 which is very slow compared to Kitkat, so I tried to flash a 4.4.4 rom for G901F but odin says it failed:

Code:

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<ID:0/003> Added!!
<OSM> Enter CS for MD5..
<OSM> Binary Check MD5.. Do not unplug the cable..
<OSM> Please wait..
<OSM> Checking MD5 finished Sucessfully..
<OSM> Leave CS..
<ID:0/003> Odin engine v(ID:3.1100)..
<ID:0/003> File analysis..
<ID:0/003> SetupConnection..
<ID:0/003> Initialzation..
<ID:0/003> Get PIT for mapping..
<ID:0/003> Firmware update start..
<ID:0/003> SingleDownload.
<ID:0/003> aboot.mbn
<ID:0/003> NAND Write Start!!
<ID:0/003> sbl1.mbn
<ID:0/003> rpm.mbn
<ID:0/003> tz.mbn
<ID:0/003> sdi.mbn
<ID:0/003> NON-HLOS.bin
<ID:0/003> boot.img
<ID:0/003> recovery.img
<ID:0/003> system.img.ext4
<ID:0/003> modem.bin
<ID:0/003> cache.img.ext4
<ID:0/003> hidden.img.ext4
<ID:0/003> FAIL! (Size)
<ID:0/003>
<ID:0/003> Complete(Write) operation failed.
<OSM> All threads completed. (succeed 0 / failed 1)
<ID:0/003> Removed!!

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So now my phone is stuck with the "Firmware Upgrade encountered an issue. Please select recovery mode in kies & try again." error. Does anyone know what does that error mean and is there anything I could do now? Is it because I tried to flash an older rom over my newer one?

Thanks!