OK so let's deal with "title is non-unique"

You have multiple areas with the same name. You should just add a suffix to these areas saying "Mesh" or "Main" - or ignore the error if you'd prefer.

Now, "path does not exist".

Say you have your flightsimulator directory set as "X:\SomeDirectory" - (Please don't set your flight simulator directory to this) and you have an area with directory set "AreaDirectory".

Then, SCE will simply check if "X:\SomeDirectory\AreaDirectory" exists. If it doesn't then the path doesn't exist - and there's no point referring to the Area in flightsim because it won't be able to find it.

What this is saying is, these scenery areas are probably not on your computer anymore and FS will not be able to load them. (Assuming of course you have set up SCE correctly with the correct flightsimulator directory and of course that there's not some strange scenery program that doesn't create these directories on starting flightsimulator.)

HTH