Unable to Login to Omni-Channel

Supported browsers for using the Lightning Experience in Salesforce are listed in the following documentation:

• Supported Browsers and Devices for Lightning Experience
• Recommendations and Requirements for All Browsers

To use Messaging for In-App and Web (MIAW), the following domains need to be allowed:

*.salesforceliveagent.com
 For Chat, Omni-Channel, and SOS.

*.salesforce-scrt.com
 For next generation Omni-Channel engagement. (Examples: Voice and messaging.)

Details are described in Allow the Required Domains. 
To use all Salesforce services, Salesforce recommends allowing all domains listed in the documentation.