Custom ROM causes boot loop

OK here is the situation - I have Sense 6/Lolipop 5.0.1 stock ROM( installed via OTA update) on the phone which works.

I have got root and got latest SuperSU and TWRP installed.

(bootloader) version: 0.5
(bootloader) version-bootloader: 3.19.0.0000
(bootloader) version-baseband: 1.26.21331147A1.16G
(bootloader) version-cpld: None
(bootloader) version-microp: None
(bootloader) version-main:
(bootloader) version-misc: PVT SHIP S-ON
(bootloader) serialno: HT4AHWM01259
(bootloader) imei: xxxxxxxxxxxxxxxxx
(bootloader) imei2: Not Support
(bootloader) meid: 00000000000000
(bootloader) product: m8_ul
(bootloader) platform: hTCBmsm8974
(bootloader) modelid: 0P6B11000
(bootloader) cidnum: HTC__039
(bootloader) battery-status: good
(bootloader) battery-voltage: 0mV
(bootloader) partition-layout: Generic
(bootloader) security: on
(bootloader) build-mode: SHIP
(bootloader) boot-mode: FASTBOOT
(bootloader) commitno-bootloader: ba1d7a63
(bootloader) hbootpreupdate: 11
(bootloader) gencheckpt: 0
all: Done!

However every time I install a custom ROM I get stuck in boot loop and the only way to fix it is to go back to stock ROM

Any ideas??