by Ken Task.
A mod_security rule was triggered ...
/etc/httpd/conf.d/mod_security.conf" line "34"
200003
You must add an exception for /repository/repository_ajax.php in mod_security rules to allow.
In conf file one could set mod_security to Detect only as below
# Default recommended configuration
# SecRuleEngine On
SecRuleEngine DetectionOnly
Check the logs and when you see a rule that would have prevented add an exception to that rule for that url
https://www.modsecurity.org/CRS/Documentation/exceptions.html
'SoS', Ken