PyTables create_array fails to save numpy array

[Gary Kshepitzki]

Why does the snipped below give:

"TypeError: Array objects cannot currently deal with void, unicode or object arrays"?

Python 3.8.2, tables 3.6.1, numpy 1.19.1

import numpy as np 
import tables as tb 
TYPE = np.dtype([ ('d', 'f4') ]) 

with tb.open_file(r'c:\temp\file.h5', mode="a") as h5file: 
    h5file.create_group(h5file.root, 'grp') 
    arr = np.array([(1.1)], dtype=TYPE) 
    h5file.create_array('/grp', str('arr'), arr)