NationalSecurityAgency/ghidra · error · IOException

Unsupported content type: {}

Error message

Unsupported content type: {}

What it means

getImmutableObject opens a FolderItem as an immutable DBTrace. It checks the item's stored contentType equals "Trace"; a different stored type (e.g. "Program", "DataTypeArchive", or a legacy/unknown type) means the file is not a trace database and cannot be opened by this handler.

Source

Thrown at Ghidra/Debug/Framework-TraceModeling/src/main/java/ghidra/trace/database/DBTraceContentHandler.java:62

	private static final DBTraceLinkContentHandler LINK_HANDLER = new DBTraceLinkContentHandler();

	@Override
	public long createFile(FileSystem fs, FileSystem userfs, String path, String name,
			DomainObject obj, TaskMonitor monitor)
			throws IOException, InvalidNameException, CancelledException {
		if (!(obj instanceof DBTrace trace)) {
			throw new IOException("Unsupported domain object: " + obj.getClass().getName());
		}
		return createFile(trace, TRACE_CONTENT_TYPE, fs, path, name, monitor);
	}

	@Override
	public DBTrace getImmutableObject(FolderItem item, Object consumer, int version,
			int minChangeVersion, TaskMonitor monitor)
			throws IOException, CancelledException, VersionException {
		String contentType = item.getContentType();
		if (contentType != null && !contentType.equals(TRACE_CONTENT_TYPE)) {
			throw new IOException("Unsupported content type: " + contentType);
		}
		DatabaseItem dbItem = (DatabaseItem) item;
		ManagedBufferFile bf = null;
		DBHandle dbh = null;
		DBTrace trace = null;
		boolean success = false;
		try {
			bf = dbItem.open(version, minChangeVersion);
			dbh = new DBHandle(bf);
			OpenMode openMode = OpenMode.IMMUTABLE;
			trace = new DBTrace(dbh, openMode, monitor, consumer);
			getTraceChangeSet(trace, bf);
			success = true;
			return trace;
		}
		catch (VersionException | IOException | CancelledException e) {
			throw e;
		}

View on GitHub (pinned to d5f144c24d)

Solutions

1. Route the item to the content handler matching item.getContentType() (use ContentHandler.getHandler for the type).
2. If the file genuinely should be a trace, recreate it as a trace file.
3. Verify item.getContentType() == DBTraceContentHandler.TRACE_CONTENT_TYPE before calling getImmutableObject.

Example fix

// before
DBTrace t = handler.getImmutableObject(item, consumer, ver, minVer, monitor);

// after
if (!DBTraceContentHandler.TRACE_CONTENT_TYPE.equals(item.getContentType())) {
    throw new IOException("Item is not a trace: " + item.getContentType());
}
DBTrace t = handler.getImmutableObject(item, consumer, ver, minVer, monitor);

if (!DBTraceContentHandler.TRACE_CONTENT_TYPE.equals(item.getContentType())) {
    throw new IOException("Item is not a trace: " + item.getContentType());
}
DBTrace t = handler.getImmutableObject(item, consumer, ver, minVer, monitor);

static boolean isTraceItem(FolderItem item) {
    return DBTraceContentHandler.TRACE_CONTENT_TYPE.equals(item.getContentType());
}

try {
    return handler.getImmutableObject(item, consumer, ver, minVer, monitor);
} catch (IOException e) {
    if (e.getMessage().contains("Unsupported content type")) {
        // dispatch to the handler for item.getContentType()
    } else throw e;
}

When it happens

Trigger: Calling getImmutableObject on a FolderItem whose contentType is not "Trace" — opening a Program file via the trace handler, or a corrupted/mislabeled item.

Common situations: Content-handler misrouting. A file renamed/converted so its contentType no longer matches. Version upgrade leaving a stale contentType. Mixed shared-project content.

Related errors

• Unsupported domain object: {}
• only DBTrace objects are supported
• File imported is not a Trace: {traceName}
• Address does not belong to a memory in the trace
• Address is not associated with a breakpoint container

AI-assisted analysis of NationalSecurityAgency/ghidra@d5f144c24d (2026-08-14). Data as JSON: /api/errors/2f9490153a2537a7. Report an issue: GitHub.