On-Call Calendar wont load post upgrade

[Anthony D2]

Hello experts,

We recently upgraded our instance to Yokohama and missed an issue where our on-call calendar view wont load. I'm getting a blank white screen under the top navigation bar, and when I look in the browser console I see an error: Failed to load resource: the server responded with a status of 401 (Unauthorized)

which was related to on_call_rotation_calendar_launcher.do

Not sure where to begin troubleshooting this. I tried repairing the on-call plugin, but it didn't seem to help.

Anyone know what I should try or should I just open a case with ServiceNow support?

Thanks!

[Mark Manders]

If something breaks due to an upgrade, start with logging a NowSupport Case (assuming you already did some searches in the release notes and community). They often take a lot of time and the Community could be faster, but at least they are already working on it as well. Or maybe they already know and can tell you what to do.

A 401 message often means that you are missing roles or something like that, but (again, assuming you already searched the release notes), it's probably something else. 

Tip for the next upgrade: make sure you document everything you found during the upgrade and also afterwards, so you won't forget to test it next time.

[kaushal_snow]

Hi @Anthony D2 ,

Ensure that the user experiencing the issue has the necessary roles assigned, such as on_call_admin or on_call_user....Review Access Control List related to the On Call Calendar to confirm that the user has the appropriate permission...Try it once..

If you found my response helpful, please mark it as ‘Accept as Solution’ and ‘Helpful’. This helps other community members find the right answer more easily and supports the community.

[JeremyHoffman]

@Anthony D2 

We have the same issue, however, the URL to the page was saved as a favorite and the end user doesn't remember how they navigated to it from within the Platform to be able to save it as a favorite. In our instance, if I navigate All--> On-call Scheduling and select either On-call Schedules or On-call Calendars, both the pages load properly. However, they URLs are different:

now/nav/ui/classic/params/target/%24oc_groups.do 

and 

now/nav/ui/classic/params/target/%24oc.do%3Fsysparm_include_view%3Ddaily%2Cweekly%2Cmonthly%26sysparm_timezone%3DUS%252FEastern%26sysparm_current_view%3Dmonthly%26sysparm_start_date%3D2025-09-29%26sysparm_timeline_enabled%3Dfalse%26sysparm_group_id%3Dbde62115db169850f52c3df339961995%26sysparm_rotas%3D1d955b7347736a18cfbc4caa116d4344%26sysparm_rosters%3D89e553b747736a18cfbc4caa116d433e%26sysparm_show_gaps%3Dtrue%26sysparm_show_conflicts%3Dtrue

- this one starts off with a redirect (/$oc_calendar_launcher_redirect.do)

Do you know how your users navigate to that page from within the platform? Also did you open a support ticket? I would but I can't document the steps to reproduce other than copying and pasting the URL.

Jeremy

[JeremyHoffman]

Hello! I submitted a question to SN Support and here is their response:

-Yes we have identified the On-call calendar module is redirecting to "/$oc_calendar_launcher_redirect.do" UI page in Yokohama release whereas it redirects to the "on_call_rotation_calendar_launcher.do" page in the Xanadu instance out-of-the-box.
-The menu arguments has changed in Yokohama to /$oc_calendar_launcher_redirect.do while opening on call calendar.
-Also you can see the application menu setting for link type - arguments

/now/nav/ui/classic/params/target/sys_app_module.do%3Fsys_id%3D4711d650c0a8170100d6a46d79493f13

-This change was made to fix a security bug as part of a problem.
I am pasting the problem number as follows for your reference:
PRB1813636

To resolve this issue, users may need to re-add their favourites.
I'm attaching ServiceNow KB Article below which explains about the above behaviour changes in Yokohama.

https://support.servicenow.com/kb?id=kb_article_view&sysparm_article=KB2206416

I hope this helps!

Jeremy