it should work as long you do by what is said notice from first page.
does it happens on particular scenario? at least does says either process game is on and trainer activation marked with red and sound?
here are few tips you could try...
1) make sure process name is named "PlagueIncEvolved.exe" (it's a rare case but hey, was just making sure)
2) UAC is off and make sure either antivirus isn't blocking the trainer and others 3rd programs such as designed for typical target adware, spyware ect.
and most important, do what is said on notice for example enter in a scenario (i tested from main game) pick a disease to play and enter in game world, pick a country to spread and gain few DNA points then alt-tab out, start the trainer (make sure with admin right) and go with hotkey activation (takes few seconds) then with cheats.