I thought I had saved the odb file when exiting LibreOffice. Now when I try to open it I get the following error message:
LibreOffice 4.1.4.2 Version Incompatibility Incorrect file version.
Therefore all my work has been lost. Not a good start.
What if anything can be done about it?
I cannot answer your questions, but since it is so particular (and apparently you fear about your data), I suggest you to raise this issue at http://webchat.freenode.net/?channels=libreoffice. Alternatively you can submit a bug (but this likely will require to attach your .odb file.)