Created playlists for two folders, creating separate M3U8 files for each. Merged those two files into a combined M3U8 file. This combined filed was in folder sequence, so that all entries for folder one were first in the file. Loading that combined playlist receives and error that a file could not be accessed. The file that could not be accessed was the first file in the second folder.
This scenario was a test created to prove a theory. The problem originated when I created 62 separate playlist files, each containing contents of a single folder, and combined them in a single file. In that case the first file in folders 2-62 could not be accessed.
I'm using V3.01 in Windows 10.
For fun I set the "Write Extended Info" option for Playlists. This forced creation of # entries in the Playlist file. Combining these files into a single file and loading it was successful.