The /home/martin/Documents folder has sub folders. Within Nautilus they cannot be seen. When the same folder is viewed from a terminal session, they are listed. They are all owned by the same user and are not hidden? The folder and it's sub folders can be copied via cp to another location, viewed and accessed from nautilus. When attempted to copy from second location back to /home/martin/Documents sub folders recognised as already there. Also to try and create a folder via File-Create Folder, nautilus recognises the folder exists!! ???? Suggestions please.
I have "solved" the "problem". First I tried to create a new folder and it immediately "disappeared".
Solution: I issued the command to force a disk check "shutdown -rF now" the resulting check found some fixes that were required, took the fix option and rebooted. Signed in and all folders were back, including the ones created during the problem period.
Maybe after 8 years of hard labour my disk is telling me something!!