I was having a strange problem with my USB dropping out when using the NEWER recovery (TWRP and Philz). Which meant I couldn't push files via ADB or Sideload. Here is my solution....
I am using Windows 7
Download Google USB driver
Make sure you have TWRP 126.96.36.199 loaded as your recovery
You may have slightly different devices show up maybe, but this is what mine showed...
Open device manager
Plug phone in and power up to bootloader
Device manager should show 'Android Device' or similar
**This is where my USB was dropping out**
Make sure TWRP 188.8.131.52 loads
Look at device manager and should show 'One Mini' with a yellow exclamation mark
I tried updating the drivers automatically and browsing to the Google USB folder that we downloaded above but just kept saying 'device driver loading failed'.
The only way I found worked was
Right click 'One Mini' and update driver
Browse my computer for driver software
Let me pick from a list of device drivers
If you have Android device listed click that, if not choose Portable device.
Click 'Have disk' and locate the Google USB Driver folder and should be able to load the .inf file.
Click from the list ADB USB device and click ok.
This should load your device and install properly.
You shoud now be able to use ADB and Sideload in Recovery now.
Let me know if this works or not as there are a couple of bits that I can't replicate as the driver is already there!