User not sync to Moodle

Version
Moodle - 2.7
Joomla - 3.4.5
JMoodle - 1.0.2

I added a user manually in joomla, however when user complained that the course is not visible. Checked in moodle and tried to enroll the user. Figured out that user is NOT appearing in moodle. Went to Jmoodle - users, saw user is only there in Joomla prntscr.com/b59xk9

When selected the users and clicked add to moodle got following error message XML-RPC Error (404): Unknown error

Kindly guide how to fix this

Hi.

You can enable debugging in Moodle to get more info about the 404 error, so we can know where the problem is coming from.

Following is the error reported once i turn debugging mode
XML-RPC Error (15058501): The given username contains invalid characters | ERRORCODE: invalidusername

Following is her username which has a problem prntscr.com/b5hdem

There are other users with username in CAPS but they are available in all three Moodle, Joomla & Joomdle

While searching for error , found a post . Following is my configuration for Administration > Site administration > Security > Site policies
prntscr.com/b5hkoo

I selected Allow extended characters in username. When i again tried adding user to Moodle, i allowed . With this i think this problem get resolved.

For security purpose i am deleting the image links shared above .