'File size limit Exceeded' when importing notes - even for small files

'File size limit Exceeded' when importing notes - even for small files
This happens even for tiny files - a few Kb.

See screenshot.
From the screenshot "JSON file size cannot exceed MB".
Notice there is no number between "exceed" and "MB".

I had my ZEPPELIN_WEBSOCKET_MAX_TEXT_MESSAGE_SIZE commented out in zeppelin-env.sh
Uncommented now and set to

export ZEPPELIN_WEBSOCKET_MAX_TEXT_MESSAGE_SIZE=4096000

but still getting the same error message.

It now prevents us from importing any notebooks.