Also, unable to import MP4 files which worked under previous Lightroom release. I get the following error message:
An unknown error occurred while reading the video file, connecting to dynamic link server failed (1)
won't recognize two versions of a file that are in jpg and tif format.
Set the option Preferences > General > Treat JPEG Files Next To Raw Files As Separate Photos. Then in the Folders panel in Library, select the folder(s) containing the TIFFs and JPEGs, right-click and do Synchronize Folder. That will import the JPEGs as separate photos.
Thanks John. I had previously captured frames from a video and saving them as tif files, and they were showing up as separate files in LR. I then installed LR 2015.10 today, and re-imported the files and came across this issue. Problem solved with your helped.
However, I can't import the video again, LR fails to load it. And I can't play any previously imported videos. Note: I've only tried MP4 videos in both cases.