After updating to Android 5.0, I can no longer find the 'My Files' application. Has this feature been disabled? If not, where is this now located?
I had the same problem. I'm using a Galaxy Samsung Tab 3 with Android 4.4. The "My Files" icon went missing.
After a lot of digging I learned that I had to click the Settings icon, then Application Manager. It would list all the downloaded apps. You must then swipe the list to the left so you can see the heading "All" and "Turned Off" hidden off to the right side. I found the "My Files" app had been turned off. Click on it to turn it back on.
Most default apps or bloatware can be disabled, try looking into settings > apps > all, and search for you application there. It could have been disabled by a mistake.
If that solution does not work then I recommend you to download ES File Explorer. In my opinion it is a better file explorer than the android default.
After installing ES, assuming you are rooted. You can navigate to the root directory "/" /system/app. And you will see every application installed by default.