Why can't i open downloaded files?

[Android Central Question]

Whenever I download a file (photo/video from the internet, music from TubeMate, apk files) it is successfully downloaded, but cannot open/install. With TubeMate, I have to restart the device after a successful download to successfully get another. I sometimes get installation glitches from Playstore, and regardless of what browser I use, the issue remains

 

[Shuvam]

try using a different file manager

 

[B. Diddy]

FYI, Tubemate violates YouTube's terms of service. Thread closed.