Due to the deprecation of the Dynamics 365 Regional Discovery service and the complete shut down of the service on the 21st of April 2021, Nintex are releasing fix packs for all K2 versions to enable customers to continue without interruptions.
If the Fix Pack is not applied a 404 error will occur when using the Dynamics 365 CRM Service Instance.
See the article from Microsoft regarding the deprecation of the Dynamics 365 Regional Discovery service:
NOTE: After installing the Fix Pack, the URL will still display as https://disco.crm. The fix is to automatically replace this in the background with the correct URL.
You need to be on the latest available Cumulative Update for your K2 version to be able to install the relevant Fix Pack. Here is a list of the versions and latest Cumulative Updates:
To determine which cumulative update or fix pack has previously been installed in your environment see KB001893.
If you need to install one of these Cumulative Updates go to Product Release and filter according to K2 Products.
Install the Fix Pack for the K2 version relevant to you: