Do stream links require a Windows or Mac based server? I added a few stream link files to my library and I'm not seeing them show up. I'm running it off a WD PR4100, using the latest beta server and testflight build on AppleTV 4k. Just sent in diagnostics 3fdf61b2-c90d-414f-8060-73cddc4ebfb1 after rescanning the library files. 
Can you screenshot one of the files and its contents? Usually issues occur when it's called strmlnk.txt instead of strmlnk
looks like they are just strmlnk to me, but I might be missing something.
See:
So the screen shot is from windows, while the DVR is running off of my PR4100. Extensions are visible: 
I did pull these strmlnk files from Maddox's github download.
Looks right.
The problem is you have Linked Movies inside the dvr folder. If you move it into Imports it will work.
/share/Channels/Imports/Linked Movies
I get a permission error when I try to add anything to the imports folder, not sure why. Everything should be writable to the share as I'm logged in. I also get a permission error when trying to move items into the PlayOn folders as well.
In the event anyone else runs into this folder permissions issue on a PR4100 share - I was able to rename the imports folder that wasn't allowing me to copy to it. I changed the name to Imports2. Then I created a new folder called Imports, and was able to copy in the strmlnk files in - Channels then imported them as expected.
