When doing Burn Bootloader or Upload Using Programmer, or whenever using the Tiny841 without bootloader, you need to select one of the programmers with (ATTinyCore) after it.
They are exact copies of the programmers of the same name defined by official avr board package; it's a workaround for a bug/feature with the IDE that causes it to use the upload recipes defined in the official avr board package, instead of the ones from the board package that goes with the board. These recipes point avrdude to an avrdude.conf that comes with the IDE. Unfortunately that version of the file doesn't support most ATTinys.