You're welcome, Winchester :)

Unless you have edited the export setup then it's unlikely you are the cause of the MERGE layer issue. I will see if this is a known bug.

That's quite understandable, Jim. No worries :)

Yes. April 4th is Thursday.

But don't worry if you miss it, Jim. They're always recorded.

Thanks :)

The first thing I did was to hide all the sheets except the BACKGROUND and used List in the Info menu to find out a bit more about the entity I could see on that sheet. This is what I got.

The first problem is that the 'polygon' isn't a polygon but 4 separate lines on the BACKGROUND sheet. The second problem is that they are on the MERGE layer, which is definitely wrong. Things on the MERGE layer cause all kinds of problems, so we need to put both those things right.

I right-clicked the Fractalise button on the left and picked "Line to Path", then picked all the lines and hit D for do it. The accidental effect of doing this with a set of lines that are perfectly alined at the corners is that they automatically become a polygon, even though that wasn't the intention of the command. It's really convenient, though, so no one complains about it.

This is what I got

I used Change Properties (top paint can button on the left toolbars) on the visible polygon to put the new polygon on an appropriate layer (BACKGROUND), and to change the fill to "Sea_Light CA51".

Then I unhid the rest of the sheets.

(In this example I changed the fill to Sea_Medium)

Here is the modified FCW for you.

In it, I have also hidden the CONTOURS LAND sheet to simplify the appearance.

This is a fairly complex map with a lot of very tiny islands and lakes. Please ask if you have any further issues with it.

Can you pease upload the .FCW file - the CC3 file?