Help with flashing tw rom topic

OK I'm on CyanogenMod 11 and want to try flashing a tw ROM every time I try it says device encryption failed and it wants me to reset and it doesn't work please help me out here,some info to help.

Twrp 2.5.0.2
And CyanogenMod 11 nightly
Please walk me through what I need to do and point me to a good touchwhiz ROM thank you all.