Originally Posted by D395267
It looks like you are trying to restore the keys whilst on a custom kernel.
Please don't do that. Only restore the keys when on official, unmodified stock kernel.
And the USB port, that must be a hardware issue. My sister's S4 had the exact same issue (I know it isn't the same device, but the problems are nigh identical) and having the USB port replaced did the trick.
I recommend that you get the USB port checked out first before you do anything else. You don't want the connection to die whilst flashing, unless you want a new paperweight
Well... didn't believe anymore that someone would answer to it... but coincidently, I really solved it. And it wasn't even difficult... but really strange.
The whole reason was the cable. I found out (only 3 days ago) that when I connect the phone to my cars USB-Port (for charging actually) my phone tells me about an ADB connection. So I though I should try again on my PC... but it didn't work. So I tried it with the semi broken cable from the car (instead of 2 (!!!) different ORIGINAL Sony cables that I tried before)... and it worked. Whyever... no idea. I mean... I tried those Sony cables before... and they always worked... on any USB Port... so no idea why this was the case now.
...sometimes strange things happen....
...but thx for your reply! I didn't try restoring before that.