I had a similar problem to this. Whenever I clicked "show in folder" in google chrome it would try to open vlc.
The solution was to right click any folder select "open with" from the context menu. Select "open with other application" from the next context menu. From the list of software that appears select your file manager application. In my case it was thunar. Then ensure "remember this application for "folder" files" selection box is ticked. Select open. Job done. From now on whenever you click "show in folder" it should open the folder with your chosen file management application.
Just to note, I know in this case it was me who changed the defaults inadvertently anyway, not any kind of software glitch, when I was experimenting with trying to add an "open with vlc player" option to the context menu on folders.
I hope this helps. My first post in here so be nice.