If you open the first png in the list on its own in Aseprite, assuming the files are named sequentially, it will trigger the same prompt the plugin uses. Does that work?
If you go to the timelapse folder (the sprite name, suffixed with _record) for a sprite, and open the first file suffixed with 0 via the File > Open dialog in aseprite - it should attempt to load all files sharing the sequence, like the included image, 
. The folder should contain an _index.txt file and all of your snapshot pngs assuming you’re using a current version.
Based on the error you are getting, that would indicate there are not any snapshots taken for the file you have open. The Open Timelapse function acts upon the currently active sprite in your editor.
I had this happen to me but then I did this: Users can also re-enable dialogs in Aseprite by selecting Edit, then Preferences, and then Alerts and ticked a box to yes that said "open a sequence of static images as an animation"and then followed the steps that sprngr recommended and it worked for me. Hope this helps