I'm using Windows 10 64-bit. Both the explorer extension and the application itself work fine, unless I try to access a directory that is a sub-directory of my Documents, Videos, Downloads, Pictures, etc. Basically anything that has a "libraries" counterpart it seems. When I do this, it either refuses to open at all, or, in the case of the explorer extension, will (sometimes) load, after up to 2 minutes. But not always. Other times it's just as fast as anywhere else. ... I have absolutely no idea what the pattern is. The same thing happens if I try to open one of those directories in the application itself. It just freezes. And in this case it never resolves, and I have to kill it. Process Explorer will show the program having been suspended, even thought I didn't do that. Occasionally even multiple instances of the program will be open, all but one suspended, and none of them with any visible windows.
To clarify: Downloads (or Documents, Pics, etc) will open, but anything below that has the problem.