Thank you for the log.
That is indeed strange:
Until the start of OpenCPN at 22:32:44: 2014-07-15 everything works fine.
But after the start at 15:15:50: 2014-07-22 OpenCPN failed to read its configuration data as documented in the log:
15:15:51: Error: Failed to convert file "C:\ProgramData\opencpn\opencpn.ini" to Unicode.
15:15:51: Warning: can't open user configuration file 'C:\ProgramData\opencpn\opencpn.ini'.
15:15:51: File C:\ProgramData\opencpn\navobj.xml seems not to be well-formed UTF-8 XML, used fallback ASCII format conversion - some text information might have not been imported.
15:15:51: Failed to load C:\ProgramData\opencpn\navobj.xml: Error document empty.
The file navobj.xml holds all your navigation
data such as routes, tracks and waypoints. When this cannot be accessed you will not be able to save any such data.
I guess something has happened to the Windows operating system between 2014-07-15 and 2014-07-22 but I don't know what because I have no knowledge about Windows. Hopefully someone other can help.
Please look if you can find any file called C:\ProgramData\opencpn\navobj.xml.5 or C:\ProgramData\opencpn\navobj.xml.4 or C:\ProgramData\opencpn\navobj.xml.3
These are backup files of navobj.xml and may contain your old data.
Delete or rename also the file C:\ProgramData\opencpn\opencpn.ini so OpenCPN is able to generate a new one.