Have you tried using Extreme Injector? My antivirus flags it as a hacktool virus so I won't use it but, I did find a modders site that claims you need it with Windows 10 for the cinematic tool to work.
http://daimodder.tum...ls-issue-solved
Thanks very much for the link/info. But unfortunately, I'm still stuck... 
The first time I tried using the Injector, Malwarebytes flagged and deleted it. I went ahead and added it to my Exceptions, and did the same with avast! as well (those are the only 2 virus/malware programs I have). I also added the DAI Cinematic Tools to the Exceptions for both programs, and then tried again. But still nothing. I'm still stuck at the stage where that second window for the DAI Cinematic Tools will not open up.
Do I have to actually do something to get that second window to open up, or is it supposed to just open up automatically after the first one opens? Like I said previously, in the tutorial she says "I usually just click on Inquisition", but I don't know what she's talking about, and can't see what exactly she's clicking. I must be missing a step here, but I don't know what/where this "Inquisition" thing is that she's talking about...
On a side note: I'm not even sure if the Injector is working. When I click "Inject" (for the last step of the instructions) nothing appears to happen. For example, the window doesn't close, there's no confirmation message, no error message, etc., etc. Basically, there's no visual confirmation at all that it worked (or didn't work).
Any other suggestions of things to try would be much appreciated. I must get this working! The thought of not being able to take custom screenshots in this game makes me want to go curl up in a corner and cry. 
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Again, my steps (with a bit more detail this time):
* Malwarebytes (commercial ver.) - Exceptions added for DAI Cinematic Tools.exe & Extreme Injector v2 by master131.exe
* avast! (free ver.) - Exceptions added for the folder that both of the above have been extracted to (avast! can only add a folder, not individual files)
1- Launch the game as Admin, using the green sword/shield icon (DragonAgeInquisition.exe), not the Origin client.
2- Load my most recent game save.
3- Tab out of the game (so I can access the DAI Cinematic Tools.exe). I play in Full Screen, and tabbing out doesn't really minimize the game, it just changes it to a small windowed version, which allows me to see and access everything on my desktop.
4- Run DAI Cinematic Tools.exe as Admin. (This only opens the first window, with the Freecamera, Visuals, and Misc tabs. The second window does not open.)
5- Run Extreme Injector v2 by master131.exe as Admin.
6- Press “Add .DLL”, browse to DAI CInematic Tools folder and add “DragonAge.dll”.
7- In the “Process name” box, write DragonAgeInquisition.exe and press Inject. (I didn't have to actually type DragonAgeInquisition.exe this time. It seems to have just remembered it from before.)
And... nothing happens. Still no second window for the DAI Cinematic Tools. I went ahead and tried to use it in-game anyway, but it's not working. The Insert and Delete keys do nothing. And I did press the NumLock key before trying again, but still nothing. (Is there any way to know when the NumLock key is on/off?)