The file manager I use is called Agent Ransack. That’s a very strange sounding name. It’s actually the free or light version of a product called FileLocator Pro. But the free version is so powerful that I have never found it necessary to upgrade to the paid version.
To me, it’s much more powerful and faster for searching files than is anything in Windows File Explorer. It allows you to specify folders to include and exclude from the search. Judicious use of this feature can make searches lighting fast. Also, that means that it can show you files from across multiple folders all on the same screen at the same time. It supports full Boolean logic. It separates the search strings that are to be found in file names from search strings that are to be found in file contents. It includes date filters. The display of files and folders is much more compact and columnized and old fashioned than that of Windows File Explorer. In other words, the display of files and folders is much better than that of the modern Windows File Explorer.
Not everyone agrees, but it seems to me that many years ago Windows seemed to have more of these kinds of features in Windows File Explorer. Microsoft then decided to make the searches supported by Windows File Manager smarter and more automated where it would do your thinking for you. But to me, it simply made Windows File manager virtually unusable for any kind of reasonable searching.
One limitation in Agent Ransack that I think is actually a good thing is that any search is static. If you search for all .TXT files in a particular folder and then add a new .TXT file to the folder, the new file will not show up in Agent Ransack until you rerun the search. By contrast, Windows File Manager is constantly monitoring for new or changed files and will show the changes automatically within a few seconds of when the changes are made. But in practice, I usually like the Agent Ransack way of doing it better.
I do still use Windows File Explorer quite a lot. It’s common for me to find a file in Agent Ransack and then with a right click go to to the folder in which the file is located using Windows File Explorer.
Agent Ransack is very integral to the way I add media files to RM. I simply locate the file in Agent Ransack, right click to get the full file path, and paste the full file path into RM. Works a charm.
I do wonder if the quotes around the file path are your problem when pasting the file path into RM. It’s hard to see why it would be, but it is suspicious.