The popular Xstream XML library (v1.3.1) used by MapTool and many other open source projects is not compatible with Java 7. If you get the message that:
Cannot determine Campaign File Format: Not loaded.
...on a campaign file that previously worked fine chances are that your system was updated to Java 7 either manually or via auto-update.
Until a new build of MapTool using the fixed XStream library is released, the only workaround at this time is to revert back to Java 6 or tell MapTool to launch using Java 6. The Java 7 install should not have removed your existing Java 6 JRE install so this is easily done.Forcing the MapTool Launcher to use Java 6
Locate the mt.cfg
file in the MapTool directory. Open it in Notepad or some other text editor. You should see something like this:
You need to provide the full path to your Java 6 executable. For Vista and Windows 7 they can be found here:
64-bit Java - C:\Program Files\Java\jre6\bin
32-bit Java - C:\Program Files (x86)\Java\jre6\bin
Edit your mt.cfg file like this for 32-bit Java:
JVM=C:\Program Files (x86)\Java\jre6\bin\javaw
For 64-bit Java use the 64-bit path.Forcing the Use of Java 6 in MapTool Batch Files
The same principle applies for those using batch files but make sure you use quotes around your path if it has spaces in it. Like so:
"C:\Program Files\Java\jre6\bin\javaw" -Xmx256M -Xss512K -jar maptool-*.jar run
If you see this message, or something similar, then you need to use quotes.
'C:\Program' is not recognized as an internal or external command,
operable program or batch file.