Deployment on serving failed

[ajinkya933]

I tried to deploy this model on google ai platform, I get this error:

WARNING: Using endpoint [https://ml.googleapis.com/]
Creating version (this might take a few minutes)......failed.
ERROR: (gcloud.ai-platform.versions.create) Create Version failed. Model validation failed: Outer dimension for outputs must be unknown, outer dimension of 'mrcnn_detection/Reshape_1:0' is 1 

Any Idea how to solve it, here's the signature def of my model:

signature_def['serving_default']:
  The given SavedModel SignatureDef contains the following input(s):
    inputs['input_anchors'] tensor_info:
        dtype: DT_FLOAT
        shape: (-1, -1, 4)
        name: input_anchors:0
    inputs['input_image'] tensor_info:
        dtype: DT_FLOAT
        shape: (-1, -1, -1, 3)
        name: input_image:0
    inputs['input_image_meta'] tensor_info:
        dtype: DT_FLOAT
        shape: (-1, 14)
        name: input_image_meta:0
  The given SavedModel SignatureDef contains the following output(s):
    outputs['mrcnn_detection/Reshape_1'] tensor_info:
        dtype: DT_FLOAT
        shape: (1, 100, 6)
        name: mrcnn_detection/Reshape_1:0
    outputs['mrcnn_mask/Reshape_1'] tensor_info:
        dtype: DT_FLOAT
        shape: (1, 100, 28, 28, 2)
        name: mrcnn_mask/Reshape_1:0
  Method name is: tensorflow/serving/predict

How can this error be fixed ?