Today I will release a new version and fix this problems.

Try to delete a function getError() at the end of file helpers.php.

It's not really a bug, but a simple warning php. It depends to some of the php.ini configuration.

However, for sites in production you should set the PHP setting "Display Errors" to off (recommended by Joomla)

In any case today will release an update.

thanks for reporting

can you provide me a Site Details.
if yes, you can use the form below the reply in tab "Site Details".

Update and uninstall not delete DB Tables. You can update from Joomla installer.

for the problem 2:
replace line 90 at /plugins/users/jsn_users/jsn_users.php with

if(count($user->privacy)) foreach($user->privacy as $key => $value)

I will modify and reload a version 1.0.10

Big Thanks! All good///
Igor

I have re-uploaded a pro version, you can download it and replace file /plugins/users/jsn_users/jsn_users.php or Re-Install.
I made some other changes