I'm running CyanogenMod13 on my galaxy S4 with TWRP 220.127.116.11 and I wanted to flash XPosed. The xposed page says that it's only compatible with SuperSU so I installed latest Stable SuperSU 2.82 and deactivated root access on CM13 in developer options. Then I tried flashing Xposed framework zip but it complained about /system beeing a read-only file system and I realized that TWRP didn't ask me anymore if I want read-only file system (which it always did before I installed SuperSU) anymore. Looking into "Mount" I see that "system" is not mounted by default but also making a checkbox there doesn't change anything even if "Mount system read-only" is not checked. BTW: Do I have to apply the mounts somehow or is activating the "checkbox" actually enough. Maybe my problem is just that system is not mounted r/w which is my current guess but I don't know how to mount it r/w now that SuperSU is installed.
Then I though, ok if mounts are incorrect in TWRP let's use FlashFire. So I selected to mount system r/w in option for flashing and started the flash. Again even if I selected mount system partition r/w flashfire reported read-only file system. I also tried downgrading to SuperSU 2.79 but same effect.
What the hell is going on since I flashed SuperSU. Is my root now partially broken? The Apps all are working fine, it's just modifying system partition is somehow not possible neither in TWRP nor FlashFire....
Any help or insight will be greatly appreciated.