Hello and welcome to the community. 
I have just tested this trainer and it loads & works perfectly fine.
There do not appear to be any similar reports in the official threads either (Starfield Cheats and Trainer for Steam & Starfield Cheats and Trainer for Xbox).
-
Make sure Starfield is updated to the latest version. Steam/Xbox is or was probably still downloading the latest update for it. Check the downloads section of your Steam/Xbox client.
-
Because the game was updated, many mods from NexusMods also need updating. In particular, Starfield Script Extender (SFSE), which you need to launch the game from if you have that particular mod.
-
If you have SFSE, you need to launch SFSE before the trainer.
WeMod Does Not Work With Starfield Script Extender (SFSE) - Fix -
Press the History button under the Play button in the trainer and make sure the most recent version of the trainer in the list is selected.