When trying to install the TCP firmware on the eye tracker, you are actually downgrading the firmware. This is not allowed to do from the EyeX settings dialog, since it should not be done under normal circumstances. That is why you got the “The file you selected was not valid” message.
Since there are valid cases where you actually want to downgrade to the TCP firmware, such as when you want to use the eye tracker on Linux or Android, it is possible to perform a downgrade using the fwupgrade32.exe (on a Windows system :)).
The fwupgrade32 is picky about its input and unfortunately crashes given the wrong input. (Which we of course should fix so that it doesn’t.)
This is the syntax for downgrading the firmware:
fwupgrade32.exe --auto <filename> --no-version-check
The “–auto” flag means that it will run the upgrade/downgrade for the first eye tracker it finds connected to the computer, which works perfectly as long as you have only one eye tracker connected to the computer.
I hope this helps!