以下のように422のエラーメッセージが出てしまう.
Started POST "/issues.xml?key=xxx" for xxx at 2013-12-29 10:16:50 +0900
Processing by IssuesController#create as XML
Parameters: {"issue"=>{"subject"=>"API custom fields", "projectname"=>”hoge"}, "key"=>”xxx"}
WARNING: Can't verify CSRF token authenticity
API calls must include a proper Content-type header (application/xml or application/json).
Filter chain halted as :verifyauthenticity_token rendered or redirected
Completed 422 Unprocessable Entity in 0.6ms (ActiveRecord: 0.0ms)
理由はこちら:
Defect #15708: Issue Post broken in 2.4.1 - Redmine
http://www.redmine.org/issues/15708
2.4.2にすれば問題なく動作しましたよ.