Ok heres a checklist and a few tips. See if any help.
1.Make sure to run injector as admin.
2. Make sure you are using one of the new hacks in the hacks section, some don't work and have been patched.
3. Is Injector set to Auto inject and close after injection?
4. Some injectors work diff on diff Os's so try diff ones.
1.Right Click your injector, choose "Troubleshoot Compatibility"
2. Let it scan and choose the Recomended Option
3. It'll ask you to open that program, do so and press ok
4. Choose to keep theese settings.
5 Run injection process as normal.
Also make sure you have the latest version of netframeworks installed. You can get it by google or bing(my fav)
Hope this helps some!