Thanks for your replies. But we are also getting 500 error code while creating topic from discourse portal.
Started POST "/posts" for 127.0.0.1 at 2018-10-22 10:08:19 +0000
Processing by PostsController#create as JSON
Processing by Presence::PresencesController#publish as */*
Parameters: {"previous"=>""}
Parameters: {"raw"=>"Good post", "title"=>"How does the Membership functionality work", "unlist_topic"=>"false", "category"=>"7", "is_warning"=>"false", "archetype"=>"regular", "typing_duration_msecs"=>"6200", "composer_open_duration_msecs"=>"179956", "shared_draft"=>"false", "nested_post"=>"true"}
Completed 200 OK in 10ms (Views: 0.2ms | ActiveRecord: 3.0ms)
Completed 500 Internal Server Error in 59ms (ActiveRecord: 9.6ms)
NoMethodError (undefined method `>' for nil:NilClass)
/var/www/discourse/lib/topic_creator.rb:161:in `setup_tags'
Please help me with this.