Error "Disconnected from Omni-Channel" When Status Is Changed to Online in Omni-Channel

1. Log in to the org
2. Switch to Lightning Experience if logged into Salesforce Classic
3. Click the app launcher and select a Console Lightning App that has Omni-Channel enabled
4. Open the browser developer tools
5. Try to make yourself online from the Omni-Channel widget. You may see the error "Disconnected from Omni-Channel. Log in again to receive work."
6. Check the Javascript console logs in the browser developer tools. You should see an error in console as well.

Possible Causes:

• Omni-Channel or Chat login time limit is maxed at 10 secs. If there has been a failure to within the last 10 secs you’ll see the message such as "Disconnected from Omni-Channel. Log in again to receive work".

• If the user is assigned to more than 200 Chat Buttons there’s a chance for timeout upon login resulting in the error message.

• If user is a member of a large number of Omni enabled queues or public groups there’s a high chance of Omni-Channel / Chat login failure after 10 secs

• Auto Greetings & Quick Texts may result in extended or delayed Omni-Channel login times

• 60% of the time goes into loading buttons (including custom greetings with field substitutions), around 20% goes into groups or queues, so if we reduce the buttons, we get a significant relief. 

• When the API Request Limit has been exceeded, review the API calls reports and limits FAQ and Omni-Channel Limit Exceeded Errors and Troubleshooting for more information.

• When the storage limit has been exceeded. If the data limit has been exceeded, new UserServicePresence records cannot be generated, so logging into Omni-Channel fails. Review this article for additional details.