JS9 in local jupyter notebook

[j-alford]

I ran the following commands:

import jjs9
jjs9.init_js9=True
J = jjs9.Js9Local(root='http://localhost:8888/')
J.NewDiv()
J.Load('pn.fits')

The command runs for a few seconds before giving this error:

JS9 ERROR: can't copy image to zscale heap: 16777216 (b.vmemcpy is not a function. (In 'b.vmemcpy(new Uint8Array(c.buffer),e)', 'b.vmemcpy' is undefined))

Any help is much appreciated.