Tencent/matrix · error · IllegalStateException

Unexpected type for

Error message

Unexpected type for 

What it means

findPath dispatches each queued node by the concrete Instance type: ClassObj, ClassInstance, or ArrayInstance. If node.instance is none of these (an unknown/unexpected heap object type from the parser), the finder cannot visit it and throws IllegalStateException.

Solutions

1. Update Matrix/Haha to a parser version matching the OS that produced the hprof.
2. Re-capture the heap dump on a supported device/OS.
3. Add a fallback branch that skips unknown instance types instead of aborting the whole search.
4. Validate the hprof (it should parse cleanly in MAT/Android Studio) to rule out corruption.

Example fix

// before
} else {
    throw new IllegalStateException("Unexpected type for " + node.instance);
}
// after
} else {
    continue; // skip unknown instance type, don't abort path search
}

boolean isKnownInstance(Instance i) { return i instanceof ClassObj || i instanceof ClassInstance || i instanceof ArrayInstance; }

try { result = finder.findPath(...); } catch (IllegalStateException e) { log.error("unsupported instance type in dump", e); }

When it happens

Trigger: The heap dump contains an Instance subtype the bundled Haha parser version does not model (e.g. a new dump format producing an unrecognized instance type) and findPath dequeues it.

Common situations: Analyzing hprof files from newer Android/ART versions with an older Haha parser; corrupted dumps yielding degenerate instance objects; mixing dump versions with an outdated Matrix analyzer.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• Unable to obtained scaled bitmap's dimensions
• Could not find char array in
• Field does not exists
• Unknown root type:
• visit bmp instance failed, lost type def of typeId:

AI-assisted analysis of Tencent/matrix@3b8293bd65 (2026-09-08). Data as JSON: /api/errors/e66e5d7268534ff0. Report an issue: GitHub.

Appendix: source

Thrown at matrix/matrix-android/matrix-resource-canary/matrix-resource-canary-analyzer/src/main/java/com/tencent/matrix/resource/analyzer/utils/ShortestPathFinder.java:285

                if (targetRefSet.isEmpty()) {
                    break;
                }
            }

            if (checkSeen(node)) {
                continue;
            }

            if (node.instance instanceof RootObj) {
                visitRootObj(node);
            } else if (node.instance instanceof ClassObj) {
                visitClassObj(node);
            } else if (node.instance instanceof ClassInstance) {
                visitClassInstance(node);
            } else if (node.instance instanceof ArrayInstance) {
                visitArrayInstance(node);
            } else {
                throw new IllegalStateException("Unexpected type for " + node.instance);
            }
        }
        return results;
    }

    private void clearState() {
        toVisitQueue.clear();
        toVisitIfNoPathQueue.clear();
        toVisitSet.clear();
        toVisitIfNoPathSet.clear();
        visitedSet.clear();
    }

    private void enqueueGcRoots(Snapshot snapshot) {
        for (RootObj rootObj : snapshot.getGCRoots()) {
            switch (rootObj.getRootType()) {
                case JAVA_LOCAL:
                    Instance thread = HahaSpy.allocatingThread(rootObj);

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