On Windows: 2008, 7 and later user should specify option -Djavatest.security.allowPropertiesAccess otherwise all tests will fail:
java.io.IOException: The requested operation cannot be performed on a file with
a user-mapped section open
        at sun.nio.ch.FileDispatcherImpl.truncate0(Native Method)
        at sun.nio.ch.FileDispatcherImpl.truncate(FileDispatcherImpl.java:91)
        at sun.nio.ch.FileChannelImpl.truncate(FileChannelImpl.java:333)
        at com.sun.javatest.TestResultCache.doWork(TestResultCache.java:327)
        at com.sun.javatest.TestResultCache.doWorkUntilDone(TestResultCache.jav
:233)
        at com.sun.javatest.TestResultCache.access$000(TestResultCache.java:54)
        at com.sun.javatest.TestResultCache$1.run(TestResultCache.java:146)
Fix failed. See next comment.
The following exception constantly appears on Windows:
An unrecoverable error happened while processing the test result cache (java.io.
IOException: The requested operation cannot be performed on a file with a user-m
apped section open)
java.io.IOException: The requested operation cannot be performed on a file with
a user-mapped section open
        at sun.nio.ch.FileDispatcherImpl.truncate0(Native Method)
        at sun.nio.ch.FileDispatcherImpl.truncate(FileDispatcherImpl.java:91)
        at sun.nio.ch.FileChannelImpl.truncate(FileChannelImpl.java:333)
        at com.sun.javatest.TestResultCache.trunkIt(TestResultCache.java:385)
        at com.sun.javatest.TestResultCache.writeCache(TestResultCache.java:722)

        at com.sun.javatest.TestResultCache.doWork(TestResultCache.java:350)
        at com.sun.javatest.TestResultCache.doWorkUntilDone(TestResultCache.java
:233)
        at com.sun.javatest.TestResultCache.access$000(TestResultCache.java:54)
        at com.sun.javatest.TestResultCache$1.run(TestResultCache.java:146)

It has nothing to do with security manager. The following steps reproduce the problem:
1. Open and start some test from testsuite
2. Stop execution before it is done
3. Exception will be thrown
4. All work with this workdir will be accompanied with exceptions because ResultCache2 will be corrupted.