I burned the boot loader with the recommended settings and the help of an Arduino Uno as ISP without any issues. Then I connected the ATtiny85 to my FTDI programmer and wanted to upload the sketch ...
Additional support for AVR-USB-MCUs of the families ATmegaXYu2/4/6 and AT90usbXYZS – e.g. Arduino Uno USB-MCU (ATmega16u2) and Micro (ATmega32u4). Optiboot (an older version) is installed by default ...