# SSO 500 Error: Failed to create or lookup user: no implicit conversion of Array into String **URL:** \ **Category:** Bug\ **Created:** [10월 11, 2016, 7:05오후 UTC](https://meta.discourse.org/t/sso-500-error-failed-to-create-or-lookup-user-no-implicit-conversion-of-array-into-string/51422 "2016-10-11T19:05:50Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Michael\_Wransky](https://avatars.discourse-cdn.com/v4/letter/m/c57346/32.png) [@Michael\_Wransky](https://meta.discourse.org/u/Michael_Wransky)\ **Post date:** [10월 11, 2016, 7:05오후 UTC](https://meta.discourse.org/t/sso-500-error-failed-to-create-or-lookup-user-no-implicit-conversion-of-array-into-string/51422/1 "2016-10-11T19:05:50Z")
We have been experiencing a persistent but elusive bug for some of our forum users. The bug prevents users from accessing the forums and only gives them the lovely: “There is a problem with your account. Please contact the site’s administrator”. Needless to say, our users get very frustrated with this. Here is a sample `env`: ```plaintext hostname tiefighter32-udacity process_id 13943 application_version 3af5b19002d921e5d9c8c0ac2b0b2ec01f682703 HTTP_HOST discussions.udacity.com REQUEST_URI /session/sso_login?sso=dXNlcm5hbWU9YW5hXzUzNDExNDYyNzUxNjkxNzYmbm9uY2U9NzYzY2EwNjZkMjQ4MjVhNzk0YTRl%0AM2M1YTkzZDFlYTEmZXh0ZXJuYWxfaWQ9NDM0MTAzNzUxNiZuYW1lPWFuYV81MzQxMTQ2Mjc1MTY5%0AMTc2JmVtYWlsPW1pbnR5c3RhdGUyMDEyJTQwZ21haWwuY29t%0A&sig=17665547f99255a7f3aae98de90eddf54eb4bf5b43da17d482bb441467efa6a6 REQUEST_METHOD GET HTTP_USER_AGENT Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.143 Safari/537.36 HTTP_ACCEPT text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8 HTTP_X_FORWARDED_FOR 23.28.142.9 HTTP_X_REAL_IP 23.28.142.9 params sso dXNlcm5hbWU9YW5hXzUzNDExNDYyNzUxNjkxNzYmbm9uY2U9NzYzY2EwNjZkMjQ4MjVhNzk0YTRl M2M1YTkzZDFlYTEmZXh0ZXJu sig 17665547f99255a7f3aae98de90eddf54eb4bf5b43da17d482bb441467efa6a6 ``` Following the backtrace the issue appears to be here: ```plaintext /usr/local/lib/ruby/2.3.0/logger.rb:507:in `error' /var/www/discourse/app/controllers/session_controller.rb:148:in `rescue in sso_login' /var/www/discourse/app/controllers/session_controller.rb:95:in `sso_login' ``` Looking at those files in the[discourse repos](https://github.com/discourse/discourse/blob/master/app/controllers/session_controller.rb#L95) doesn’t make it clear but I am wondering if the error is being thrown because a `to_s` or `to_url` is being called on an array and if a `.first` needs to be called to avoid the error. Like I stated above this has been a persistent and annoying error for our users so a fix would be greatly appreciated! ---
**Author:** ![lkramer](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/lkramer/32/83897_2.png) [@lkramer](https://meta.discourse.org/u/lkramer)\ **Post date:** [10월 13, 2016, 2:33오후 UTC](https://meta.discourse.org/t/sso-500-error-failed-to-create-or-lookup-user-no-implicit-conversion-of-array-into-string/51422/2 "2016-10-13T14:33:28Z")
For what it’s worth. We’ve had a few members encounter this lately as well and I was able to make it happen once myself but it’s not consistently reproducible for us. ---
**Author:** ![sam](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/sam/32/102149_2.png) [@sam](https://meta.discourse.org/u/sam)\ **Post date:** [10월 13, 2016, 9:22오후 UTC](https://meta.discourse.org/t/sso-500-error-failed-to-create-or-lookup-user-no-implicit-conversion-of-array-into-string/51422/3 "2016-10-13T21:22:18Z")
Sorry about that, it was a bug in the cake day plugin, I deployed a fix ---
**Author:** ![codinghorror](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/codinghorror/32/110067_2.png) [@codinghorror](https://meta.discourse.org/u/codinghorror)\ **Post date:** [10월 13, 2016, 9:37오후 UTC](https://meta.discourse.org/t/sso-500-error-failed-to-create-or-lookup-user-no-implicit-conversion-of-array-into-string/51422/4 "2016-10-13T21:37:01Z")
@tgxworld cakeday is causing us so much pain. What can be done about this? I’ve seen more bugs with this plugin than the last 5 we built combined. Something is very wrong here. ---
**Author:** ![codinghorror](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/codinghorror/32/110067_2.png) [@codinghorror](https://meta.discourse.org/u/codinghorror)\ **Post date:** [10월 13, 2016, 9:37오후 UTC](https://meta.discourse.org/t/sso-500-error-failed-to-create-or-lookup-user-no-implicit-conversion-of-array-into-string/51422/5 "2016-10-13T21:37:35Z")
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**Author:** ![tgxworld](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/tgxworld/32/106117_2.png) [@tgxworld](https://meta.discourse.org/u/tgxworld)\ **Post date:** [10월 14, 2016, 8:23오전 UTC](https://meta.discourse.org/t/sso-500-error-failed-to-create-or-lookup-user-no-implicit-conversion-of-array-into-string/51422/7 "2016-10-14T08:23:11Z")
There are two problems here: 1. Accessing a plugin custom fields may return a `String` or an `Array` and there isn’t any protection for plugin authors here. If I do `user_custom_fields["date_of_birth"] = "2016-05-02"` I should ideally always get back a `String` if I retrieve the custom fields again. Currently, accessing custom fields may return an `Array` if custom fields with the same name and user\_id is somehow set around the same time. This is not ideal IMO as either all access to a plugin custom fields will have to be accompanied by a check to see if it is an `Array` or `String` or a lock has to be used when setting any custom field. 2. Maintaining a valid date as a String is not ideal. Initially when I started working on the plugin, we decided to store the date in a `UserCustomField` instead of `User#date_of_birth` because the requirements for the plugin was simple and we can get away with it even if the `date_of_birth` is invalid. Right now, we use the date of birth field in more places and an invalid format will just blow things up. I’ll look to see if I can migrate custom fields into `User#date_of_birth` to ensure consistency in the date format.