Theano bug during merge

Hello,

I am playing around with lesson 5 notebbok, and was testing how merge layers work with different bits of data. However at some point I got the following message when trying to fit a model, and subsequently it appears whenever I try to fit a model (including ones in the original notebok that worked fine).
message text:

!! BUG IN FGRAPH.REPLACE OR A LISTENER !!>> <type ‘exceptions.TypeError’> (‘The type of the replacement must be compatible with the type of the original Variable.’, Subtensor{:int64:}.0, Subtensor{int64:int64:int64}.0, TensorType(float32, (True, False, False)), TensorType(float32, 3D), ‘local_subtensor_merge’) local_subtensor_merge
ERROR (theano.gof.opt): Optimization failure due to: local_subtensor_merge
ERROR (theano.gof.opt): node: Subtensor{:int64:}(Subtensor{::int64}.0, ScalarFromTensor.0)
ERROR (theano.gof.opt): TRACEBACK:
ERROR (theano.gof.opt): Traceback (most recent call last):
File “/home/ubuntu/anaconda2/lib/python2.7/site-packages/theano/gof/opt.py”, line 1807, in process_node
fgraph.replace_all_validate(repl_pairs, reason=lopt)
File “/home/ubuntu/anaconda2/lib/python2.7/site-packages/theano/gof/toolbox.py”, line 309, in replace_all_validate
fgraph.replace(r, new_r, reason=reason, verbose=False)
File “/home/ubuntu/anaconda2/lib/python2.7/site-packages/theano/gof/fg.py”, line 561, in replace
str(reason))
TypeError: (‘The type of the replacement must be compatible with the type of the original Variable.’, Subtensor{:int64:}.0, Subtensor{int64:int64:int64}.0, TensorType(float32, (True, False, False)), TensorType(float32, 3D), ‘local_subtensor_merge’)