Users are unable to successfully log into and access Microsoft applications such as Outlook, Excel, Word, etc. on an Android device. Upon opening up one of these apps, entering in one's username, and being redirected to the Application Portal sign-in page, the following message is seen on the Android device:
Can't connect to the server
An error occurred when setting up a secure connection on the server. The security configuration on the server might be incompatible with this version of Office or your device might be missing the required security certificate for this server. Please contact your admin or ask the Microsoft community at https://answers.microsoft.com for the help with installing the certificates.
This message can be caused by an incorrect certificate being uploaded to the Cloud Administration Console > My Account > Company Settings > Company Information page. This creates an issue with the certificate chain of trust, which leads to the Android device not trusting the certificate used for connecting to the identity router.
Upload the correct certificate to the Cloud Administration Console > My Account > Company Settings > Company Information page so that Android devices trust the certificate used to connect to the identity router.