Hi, since you also contacted Docentric support, we continued troubleshooting there.
There are several possible reasons for this issue. We suggested upgrading Docentric, but that can not be the problem since you are already using the latest version.
We then focused on whether or not the problematic users have the ExternalId. You can check this in the All Users table:
Without an ExternalId, a user cannot print to SharePoint. If a user tries to use SharePoint without the ExternalId, it will result in the same error message:
“One or more parameters (_spSiteUrl, _extUserId) are not set”.
But as you told us, the users who had issues did not have an ExternalId even though they are logged in, belong to the same Azure AD, and are internal users.
We recommend you contact your administrator to find out why the ExternalIds are missing, and then possibly engage Microsoft if that does not yield results.
Would you please keep us in the loop of what you find out?