Sounds like your Atmel Studio is set to use a USBtinyISP. Perhaps one of the other programmer options will work. If they have an option for "Arduino Bootloader" then I would try that. If not, some serial device that uses the STK500 protocol should be close enough.
For Atmel Studio questions you might have more luck in the AVRFreaks.net forums.
Just in case you found this thread with an AdaFruit trinket, as I did: don't forget you need to activate the boot loader before uploading a sketch from the IDE. If you don't activate the boot loader first the trinket is not ready for upload, and you get the error message above.
Yes, it is in the documentation, but as a trinket newbie you may have missed it, as I did, and think your board is broken. It isn't.