The users are not able to log in to the app and see only a loader because there are duplicate fields with the same API names in Salesforce related to the PK4 TimeTracker application.

Please check if there are any duplicate fields in Salesforce for the PK4 TimeTracker application with the same API names. This happens if you have created a field with the same name as it already exists in the PK4 TimeTracker application.

The users cannot log in to the PK4 TimeTracker application on the device, Web page, or within Salesforce and track time until you remove the fields with duplicate API names.

Please change the field name or delete the duplicate field to fix the login or the Check-In issue in Salesforce.