4.9.x and 5.1.x LibreCalc no longer allow access to file from HD and back up flash drive

Today, I tried to open, modify, save then open an LibreOffice file. When I attempted to open the file the second time, my computer processed then failed to open the file.

Now, to access any files, I have to open LibreOffice, choose Calc, “recover” a little used file then select a poorly marked file from a group of about 15 files with large graphic shortcuts.

What a pain and what happened ?

Steve