SilentVIP has definitively stopped the development of AGSTool, so you have to try to find the game.id in another way.
Let's take Unavowed as example.
1) Open the game's exe file with a hexadecimal editor.
2) Search Adventure Creator Game File v2
3) The name of the game must be found immediately after the version of the file (for example for Unavowed it's 22.214.171.124
4) The id is a 4-byte hexadecimal value that must be searched among all a pile of zero. This ID must be found shortly after the name of the game found previously and after 222.
If you have trouble finding it you can use TRA Creator.exe but be careful the 0 is not taken into account.
It's therefore advisable to use both methods together
So for now we have the name of the game "55.6E.126.96.36.199F.77.65.64
" which is the name of the game and the key "D4.19.5A.09
Let's open the hexadecimal editor to create our game.id file. Let's enter 55.6E.188.8.131.52F.184.108.40.206da.19.5a.5a.09
but the i.d. is not complete, the number of hexadecimal positions for UNAVOWED is missing at the beginning.
there are 8 positions. the final i.d. is therefore "08.55.6E.61.76.6F.220.127.116.11da.19.5a.09