This appears to be a problem for many people, with many trainers, so perhaps a walk-through could be posted to the main forum site? Apologies if this has already been done and I haven't found it yet.
Microsoft already has a good article for how to troubleshoot this kind of issue so it would be mute to re-write it:
1. Your AV, firewall or other security software blocking this or other files that the trainers need to run. Not all trainers require these files, it depends on the trainer maker, the template needed, the game being 32bit or 64bit and a multitude of other factors. Some AV products still block memory injections even when disabled. Whitelisting the trainer itself may not work because the trainer also needs these other files from the Windows temp folder in order to run.
2. You are not right clicking run as admin on the trainer so it doesn't have permission to attach itself to the game process.
3. You do not have full rights over the Windows temp folder where these files are written and need to run from.
There you go, guide written.
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