Installing Issues with cm-12.1-20151006-NIGHTLY-serranoltexx

Hi all i have a Samsung S4 mini running CM 12.1 i cant install nightly release 1006 i get these errors:

Code:

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Finding Update Package
Opening Update Package
Verifying Update Package
Installing Update
Detected filesystem ext4 for /dev/block/platform/msm_sdcc.1/by-name/system
Detected filesystem ext4 for /dev/block/platform/msm_sdcc.1/by-name/userdata
Cannot install this package ontop of incompatible data. please try another package or run a factory reset
E:Failed to install /sideload.package.zip (not fully sure couldnt read it due to the android logo at the back but i am sure thats right)
E: Please take note of all the above lines for reports

Installation Aborted

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I have tried moving the zip to SD card and running the install and still no luck


any ideas will be greatly appreciated :D

Thanks in advance for all help