microg/GmsCore · error · IllegalStateException

DataBuffer reference of type

Error message

DataBuffer reference of type 

What it means

Thrown in SingleRefDataBufferIterator.next when the element returned by dataBuffer.get(0) is not a DataBufferRef. This iterator caches a single reusable ref object, so it requires buffers whose elements are DataBufferRef instances; the actual type is appended to the message.

Source

Thrown at play-services-base/src/main/java/com/google/android/gms/common/data/SingleRefDataBufferIterator.java:30

@Hide
public class SingleRefDataBufferIterator<T> extends DataBufferIterator<T> {
    private T element;

    public SingleRefDataBufferIterator(@NonNull DataBuffer<T> dataBuffer) {
        super(dataBuffer);
    }

    @Override
    public T next() {
        if (!hasNext()) {
            throw new NoSuchElementException("Cannot advance the iterator beyond " + position);
        }
        ++position;
        if (position == 0) {
            element = dataBuffer.get(position);
            if (!(element instanceof DataBufferRef)) {
                throw new IllegalStateException("DataBuffer reference of type " + element.getClass() + " is not movable");
            }
        } else {
            ((DataBufferRef) element).setDataRow(position);
        }
        return element;
    }
}

View on GitHub (pinned to 157c9d86ac)

Solutions

1. Use a DataBuffer implementation whose get() returns DataBufferRef instances
2. Use DataBufferIterator or a plain iterator for buffers returning other element types

When it happens

Trigger: Thrown at play-services-base/src/main/java/com/google/android/gms/common/data/SingleRefDataBufferIterator.java:30 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of microg/GmsCore@157c9d86ac (2026-09-06). Data as JSON: /api/errors/c4dd6d0f231cc310. Report an issue: GitHub.