@Override
	public String[] getSubfolderList(String folderPath) throws IOException {
		synchronized (syncObject) {
			validate();
			RepositoryFolder folder;
			try {
				folder = repository.getFolder(currentUser, folderPath, false);
			}
			catch (InvalidNameException e) {
				throw new AssertException();
			}
			if (folder == null) {
				return new String[0];
			}
			RepositoryFolder[] subfolders = folder.getFolders();
			String[] subfolderNames = new String[subfolders.length];
			for (int i = 0; i < subfolders.length; i++) {
				subfolderNames[i] = subfolders[i].getName();
			}
			return subfolderNames;
		}
	}
Verify that the client is active and continuing to read events
Ghidra/Features/GhidraServer/src/main/java/ghidra/server/remote/RepositoryHandleImpl.java