Autocomplete not working when comment present in cell

If I add a comment in a cell, the autocomplete function in Jupiter notebook stops working. Pressing TAB after writing something autocompletes to the first match but it does not show other matches for the current typed text. Pressing SHIFT+TAB should show a window with a reference to the typed function. When there is no comment in the cell both keyshortcuts work well. In the console I get the following error when pressing TAB in a cell with a comment:

[MetaKernelApp] ERROR | Exception in message handler: Traceback (most recent call last): File "/anaconda3/envs/py27/lib/python2.7/site-packages/ipykernel/kernelbase.py", line 233, in dispatch_shell handler(stream, idents, msg) File "/anaconda3/envs/py27/lib/python2.7/site-packages/ipykernel/kernelbase.py", line 452, in inspect_request content.get('detail_level', 0)) File "/anaconda3/envs/py27/lib/python2.7/site-packages/metakernel/_metakernel.py", line 584, in do_inspect cursor_pos=cursor_pos) File "/anaconda3/envs/py27/lib/python2.7/site-packages/metakernel/_metakernel.py", line 759, in get_help_on return help_magic.get_help_on(expr, level, none_on_fail, cursor_pos) File "/anaconda3/envs/py27/lib/python2.7/site-packages/metakernel/magics/help_magic.py", line 109, in get_help_on elif not info['magic']['name']: KeyError: 'name'

it happened to me also. might be this is caused by " % means magic commands in jupyter"

I'll see metakernel codes whether it's possible to avoid this error or not