cp: -r not specified; omitting directory '/home/administrator/Documents/myfile.10'
myfile.10 is a directory.
cp won't copy it, unless you explicitly use
-r (or equivalent) flag.
cp in my Debian these are equivalent:
--recursive. POSIX, however defines
-R only (
-r is mentioned as obsolescent). It says:
If source_file is of type directory, the following steps shall be taken:
-R option was not specified,
cp shall write a diagnostic message to standard error, do nothing more with source_file, and go on to any remaining files.
The conclusion is your
cp does exactly what it's supposed to do. If you want to copy the whole directory, use
-R. If you expected
myfile.10 to be a file then you need to investigate why the discrepancy.