Error when converting with merge layer

[dangz90]

Hi,

When I try to convert my caffe model I receive the following error:
ValueError: "concat" mode can only merge layers with matching output shapes except for the concat axis. Layer shapes: [(None, -1L, 27L, 64), (None, -1L, 27L, 128), (None, -1L, 27L, 32), (None, -1L, 27L, 32)]

It is quite strange that in the shape of the layer contains an L and is -1.