Birdseye fill gone missing overnight

I began a map yesterday afternoon but when I opened the map this morning the Water Fresh fill wasn't there - all I had both on the DRAWTOOLSP panel and my map was a red X. I checked the bitmap tiles and the tile is there.
What has gone wrong?
Comments
It sounds like an issue with the reference to the file.
Open the Fill Style Properties dialog and check the referece highlighted below in the text box called file:
It should be
@Bitmaps\Tiles\Overland\Annual Birdseye Continental\Water Fresh_HI.PNG
(yours may have a different resolution suffix, like VH, LO or even VL. That's normal and nothing to worry about)
EDIT:
If that's not it, use LIST to find out what fill the polygon is filled with to make sure it's a problem with the Water Fresh fill and not some other fill you might have imported.
LIST is saying that it’s Water Fresh_LO.PNG Sue. The path is OK and I haven’t imported anything.
Please can you upload the FCW? It's clearly something I haven't thought of but which might be easier to assess if it's happening right in front of me.
Here it is
Thanks :)
This is where the problem gets tricky to diagnose. The ony red X I have is the image - because I don't have that image myself.
As a last ditch attempt on my part, does the problem go away if you save and restart CC3?
If I doesn't work, I don't know everything there is to know about CC3 by many miles, so it's probably something relatively simple I've just never come across before.
I’ll have a go at restarting Windows as well as CC3+
If it doesn't work, double check just one last time that nothing has changed about the bitmap files - situation and naming, then contact Tech Support for help.
The fill should be with the rest of the Birdseye fills in the C:\ProgramData\Profantasy\CC3Plus\Bitmaps\Tiles\Overland\Annual Birdseye Continental folder (or alternative drive if you aren't using the C drive), and they should be named exactly like this.
Starting CC3+ did the trick!
Excellent! :D
I have no idea why it didn't work right the first session, but hopefully it won't happen again.