Having issues with converting from title to filename

Here is what I did I used to have some Featurettes folders in some movie folders that I have edited in the past but not all movies folders had trailers. So I have just recently downloaded (8) movie trailers and placed them inside there main movie folders and added titles to the movies like this "%title%%dummy%" from the path and it added the "Titles" correctly otherwise "men in Black (1997) would have looked like this "MEN IN BLACK [1997] - Official Trailer (HD)" without the quotes. But instead the title look correct now I'm trying to take the title and rename the file name by going like this "Tag - Filename" and then just %title%" what am I doing wrong her is the error I keep getting. "File "G:\Need To Fix\Men in Black (1997)\MEN IN BLACK [1997] - Official Trailer (HD).mp4" cannot be renamed to "G:\Need To Fix\Men in Black (1997)\Men in Black (1997).mp4".
Cannot create a file when that file already exists." "Here is the example ""G:\Need To Fix\Men in Black (1997)\MEN IN BLACK [1997] - Official Trailer (HD).mp4" ->
"G:\Need To Fix\Men in Black (1997)\Men in Black (1997).mp4" this is from preview and it looks fine but it wont complete.

Never mind I fixed it once I have the titles added I just moved all the files with titles from there main folders to a folder called "Trailers" and then renamed the properly.

I assume that your filesystem does not discriminate the case of the filename. so,

is the same as

Could you post screenshots of the dialogues and parameters you used?

I had the Trailer moved to the main movie folder before trying to rename it so I was going to have (2) files with the same name. I was going to bulk rename all the "Trailers" with Bulk Renamer Utility by replacing the ) with this )-trailer and I forgot I didn't move the files from the main movie for to the Featurettes folder so I just grabbed the titles from the path location without the word Featurettes and I would have had the main movie Men in Black and then trailer Men in Black both inside the same folder. So I went to the main Need to fix folder and did a simple search for mp4 and everything that had a title I moved to the folder Trailers and then used the Bulk Renamer Utility to change the ) to )-trailer and it worked great I then just had to move them from Trailer to the main movie folders which only took like a minute or so. Not to bad. So all has been figured out. I was going to have both mp4s with the same name that was the only issue but simple fix just move all the trailers once I had titles added because then I knew what the trailers named had been since the titles had been from youtube and not all with the same name as Trailers. Since these (8) files did not have a Featurettes folder since thery had not had trailers before. But now all trailers has been renamed from external hard drive so as of today I have added trailers to (331) movies and also removed extrathumbs and extra fanart folder as well as the Featurettes folders once I fixed the naming issues with all the trailers. I had trailers for over 300 from before they just had been inside the Featurettes folder and been named Trailers which was not being used by kodi so I need to rename all trailers from Featurettes the actual name of the movie and add -trailer to the file name. which was easy enough with the mp3tag but the harder part was with the movies without the folder Featurettes since there had been 8 movies without trailers from before so I forgot they had not been inside a Featurettes folder and had been only inside the main movie folder along with the main movie mp4 so that is why the naming had not worked but I did manage to add title based on file path and then moved them to the Trailer folder and then fixed the issue. So all done so far now i just need to place all of the movies currently on my PC to the Need to Fix folder on External Hard drive to fix all of them and delete them from my laptop.