Suddenly my Android Studio stopped detecting all my devices, none of them is working. It happen from one execution to another. I've changed a few lines of code (1 min maybe?), hit run (instant run) and then I missed all my devices.
I'm using a Mac and as devices: Nexus 5x, Galaxy s6 and Oneplus One. What can be happening? I've checked previous questions here and tried all this:
Tools > Android > Enable ADB integration
Well, I've fixed. The problem in case any faces the same was a Stetho (http://facebook.github.io/stetho/) tab in chrome, the one you open by typing: chrome://inspect/#devices not sure about the reason because it's been open for 2 days now, but it was the cause, once I closed it, it worked.
Found this unaccepted answer here: macbook adb cannot open interface That for sure should be accepted.
EDIT: I've been able to replicate the problem. It happens when you have the devices tab open and try to run a second app that has stetho configured.