Broken File, Access Denied, or Unsupported Image Format

Happy New Year,
 
In addition to viewing images, I use FastRawViewer as a file organizing tool. When reviewing assets from my phone or cameras, the folders also include videos. I've exposed the MP4 files so that I can include them when moving assets to new folders. If I didn't do this, a folder might appear empty (when there are, in fact, videos from iPhone live photos, or movie files from the most recent import).
 
When I'm in fullscreen mode and navigating with the arrow keys, if a MP4 file is selected, I get the message "Broken File, Access Denied, or Unsupported Image Format" This is OK. However, the arrow keys become disabled. I cannot press left or right to advance to the next file. I believe this is incorrect behavior; we should be able to advance from an unsupported file.
 
Thanks!
Matt