hiduino:
Your circuit is missing the USB level conversion needed for the D- and D+ lines. You need to add 3.6V zener diodes for any USB interfacing directly to Atmel AVR chips. The 5V pin levels of the 32U4 is over driving the USB data lines. All the schematic references for Leonardo and Micro use the zener diodes for level conversion.See this reference:
Ok, I did it and same problem, nothing changes.
At first I tried with two zener diodes, same as the reference you post and doesn`t work, same error from initial post.
Then I added the pull up resistor (1k) and things get worst, but after that I removed the resistor and same error from initial post.
I am really lost with this problem...