Just started having this issure today, last week when I installed the rom all was good. It allowed me to mount system/app without an issue. Now today I cannot get rw in system/app folder no matter what I try. I know I can still do it in recovery, but I really got so use to doing ti this way on all my phones. When I had the stock rom I had to be quick on bootup and open root explorer and hurry to system/app folder and click rw and it would mount ok. I just tried that on here no go either EDIT: i fixed my issue. I had to reroot no idea why but its working now.