Environment: Sharepoint Online + K2 Five 5.3

Hi,

after upgrade from 4.7 to 5.3, there is problem with opening K2 via Sharepoint list. Every user see thist error message: " The remote name could not be resolved: 'login.microsoftonline.com' "

When user use direct link to K2, it works. And after it, normal way via sharepoint works too.

K2 reaction: 

As to why accessing the Runtime site before accessing a SharePoint Form resolves the issue momentarily is because a Token is created for the user and stored in browser cookies. It remains valid and also give the user access to K2 Form in SharePoint.

As the issue was not occurring on the previous environment, I must assume that this is caused by something environmental.

Have someone some tips or solution? in this case, it is about 3000 users and it is critical error for client...

Thx, Jan