Do you ever have trouble opening a trainer? for example as shown below:
Slight problem would be great. You can not open the trainer and there is written that trainers need cheat engine 6.3 when you have installed the cheat engine 6.3 
the problem is "Perhaps you didn't properly install ce6.3 or window8 is behaving like Vista again. Anyhow, when creating a trainer pick the bloated option, so the trainer works without the cheat engine runtime installed "
This is Solution:
1. Open your Cheat Engine Folder
2. Open Uninstal Cheat Engine
3. Instal Cheat Engine Again
4. Download File Ceregreset.zip below
5. Open it
6. Try again open your trainer
7. finish

Note:
If you still have this issue, do not hesitate to ask your problems, me certainly help you so that you become a true cheater!