Description of problem:
After we upgrading the environment we are unable to access the alert tab from the UI.

~~~
[----] I, [2018-12-04T15:16:56.739301 #20752:10c794c]  INFO -- : MIQ(Api::TagsController.log_request) Request:        {:method=>:get, :action=>"read", :fullpath=>"/api/tags?expand=resources&attribute
s=category,categorization", :url=>"https://hostname/api/tags?expand=resources&attributes=category,categorization", :base=>"https://hostname", :path=>"/api/tags",
 :prefix=>"/api", :version=>"3.0.0", :api_prefix=>"https://hostname/api", :collection=>"tags", :c_suffix=>nil, :collection_id=>nil, :subcollection=>nil, :subcollection_id=>nil}
[----] I, [2018-12-04T15:16:56.739820 #20752:10c794c]  INFO -- : MIQ(Api::TagsController.log_request) Parameters:     {"expand"=>"resources", "attributes"=>"category,categorization", "action"=>"index
", "controller"=>"api/tags", "format"=>"json", "body"=>{}}
[----] E, [2018-12-04T15:16:57.713157 #20752:10c794c] ERROR -- : MIQ(Api::TagsController.api_error) API Error
[----] E, [2018-12-04T15:16:57.713260 #20752:10c794c] ERROR -- : MIQ(Api::TagsController.api_error) NoMethodError: undefined method `name' for nil:NilClass
[----] E, [2018-12-04T15:16:57.713517 #20752:10c794c] ERROR -- : MIQ(Api::TagsController.api_error) API Error

~~~


Version-Release number of selected component (if applicable):
5.9.5.3

How reproducible:


Steps to Reproduce:
1.
2.
3.

Actual results:


Expected results:


Additional info: