When jhat's main page and histogram page are accessed in quick succession, sometimes
the following exception trace results:

Exception in thread "Thread-2" java.lang.RuntimeException: invalid array element type: 0
        at com.sun.tools.hat.internal.model.JavaValueArray$ValueHolder.elementSize(JavaValueArray.java:75)
        at com.sun.tools.hat.internal.model.JavaValueArray$ValueHolder.readValue(JavaValueArray.java:88)
        at com.sun.tools.hat.internal.model.JavaValueArray$ValueHolder.getValue(JavaValueArray.java:53)
        at com.sun.tools.hat.internal.model.JavaValueArray.getValue(JavaValueArray.java:145)
        at com.sun.tools.hat.internal.model.JavaValueArray.getSize(JavaValueArray.java:171)
        at com.sun.tools.hat.internal.model.JavaClass.getTotalInstanceSize(JavaClass.java:351)
        at com.sun.tools.hat.internal.server.HistogramQuery$3.compare(HistogramQuery.java:58)
        at java.util.Arrays.mergeSort(Arrays.java:1275)
        at java.util.Arrays.mergeSort(Arrays.java:1286)
        at java.util.Arrays.mergeSort(Arrays.java:1286)
        at java.util.Arrays.mergeSort(Arrays.java:1287)
        at java.util.Arrays.mergeSort(Arrays.java:1286)
        at java.util.Arrays.mergeSort(Arrays.java:1286)
        at java.util.Arrays.mergeSort(Arrays.java:1286)
        at java.util.Arrays.mergeSort(Arrays.java:1286)
        at java.util.Arrays.mergeSort(Arrays.java:1286)
        at java.util.Arrays.mergeSort(Arrays.java:1286)
        at java.util.Arrays.mergeSort(Arrays.java:1286)
        at java.util.Arrays.mergeSort(Arrays.java:1286)
        at java.util.Arrays.sort(Arrays.java:1214)
        at com.sun.tools.hat.internal.server.HistogramQuery.run(HistogramQuery.java:64)
        at com.sun.tools.hat.internal.server.HttpReader.run(HttpReader.java:181) at java.lang.Thread.run(Thread.java:626)
Exception in thread "Thread-1" java.lang.RuntimeException: invalid array element type: 0
        at com.sun.tools.hat.internal.model.JavaValueArray$ValueHolder.elementSize(JavaValueArray.java:75)
        at com.sun.tools.hat.internal.model.JavaValueArray$ValueHolder.readValue(JavaValueArray.java:88)
        at com.sun.tools.hat.internal.model.JavaValueArray$ValueHolder.getValue(JavaValueArray.java:53)
        at com.sun.tools.hat.internal.model.JavaValueArray.getValue(JavaValueArray.java:145)
        at com.sun.tools.hat.internal.model.JavaValueArray.getSize(JavaValueArray.java:171)
        at com.sun.tools.hat.internal.model.JavaClass.getTotalInstanceSize(JavaClass.java:351)
        at com.sun.tools.hat.internal.server.InstancesCountQuery.run(InstancesCountQuery.java:118)
        at com.sun.tools.hat.internal.server.HttpReader.run(HttpReader.java:181) at java.lang.Thread.run(Thread.java:626)