Additional to what Daiya posted, think of a custom dictionary as being an
"auxiliary" dictionary that's used in addition to the actual dictionary
files used by Word. Any terms you add are actually added to your custom
dictionary, not to the main ones supplied by the program. You can also have
more than one custom dictionary. The custom dictionary files are stored in a
location of your choice when you create them & Word 'remembers' where they
are. As long as you don't move or delete them they present no problem.
The main dictionary files, however, are copied to a specific location when
Office is installed & need to remain there. If it can't find them when
called for you would get some sort of error, and since you reported nothing
like that it's pretty safe to assume that the main dictionary files are
where they should be and that the reason there is nothing found to be
incorrectly spelled is most likely some other issue.
Additionally - I don't think this is in the material she referred you to -
go to Word> Preferences> Spelling & Grammar to make sure there isn't a check
in the box labeled "Hide spelling errors in this document". You might also
click the Check Document button while there, then recheck the spelling...
It's possible that during a previous spell check the Ignore/Ignore All
option was used.
HTH |:>)
Bob Jones
[MVP] Office:Mac