I updated my HTC One m8 to Lollipop and rooted it. I have programs that require the ability to write to external SD card like FileMount, but every time I launch FileMount it tells me that it can't write to SD card. The app itself has a feature to enable it automatically but it requires a reboot but still even after reboot the same problem occurs.
When I was on android 4.4.4 I tried installing sd fix but that thing didn't work. I installed Xposed installer and installed HandleExternalStorage module and it worked great for me. But I can't use Xposed installer on Lollipop as the developer says it might not be possible for Xposed installer to be available for Lollipop. My device is 16 GB only and it's really not enough for me and I rely on FileMount for my storage issues.