shape mismatch: value tensor of shape [3, 1] cannot be broadcast to indexing result of shape [3]

This error occurs when there is a mismatch between the shape of the value tensor and the shape of the indexing result in a TensorFlow operation.

In this specific case, the error message is saying that a value tensor with shape [3, 1] (3 rows and 1 column) cannot be broadcast to an indexing result with shape [3] (3 elements).

Broadcasting is a technique used in TensorFlow to match the shapes of tensors when performing operations. However, in this case, the shapes cannot be broadcasted because they are not compatible.

To fix this error, you need to ensure that the shape of the value tensor matches the shape of the indexing result. One way to do this is to reshape the value tensor to have the same shape as the indexing result. For example, you could reshape the [3, 1] tensor to [3] by using the `tf.squeeze()` function:

value_tensor = tf.squeeze(value_tensor)

Alternatively, you could adjust the indexing operation to match the shape of the value tensor. For example, you could use an indexing operation that returns a tensor with shape [3, 1], such as:

result = tensor[indexes, tf.newaxis]

where `tf.newaxis` adds an extra dimension to the tensor, resulting in a shape of [3, 1].