No module named 'numpy._core'

I can't seem to get a good docker environment build now that doesn´t give me this error:
>>> No module named 'numpy._core'
when I run 
$ dacfile=dac.DACFile.load(fpath)

I guess there is a library incompatibility somewhere, but I haven´t had any success finding it yet. Has anybody else seen (and solved) this?

Thanks