User Receives an Error after Lightning Experience is Enabled

This is mainly caused by the Company Information being inaccurate.


Navigate to your organization's Company Information page to check the details:


In Salesforce Classic

1. Click Setup

2. Click Company Profile 

3. Select Company Information

In Lightning Experience

1. Go to Setup.

2. On the Quick Find box, enter Company Information and click it from the options that will appear.

After performing the above steps, confirm if the user added to the Primary Contact field is active. If not, replace him or her with an active user. Then click Edit and Save on Company Information.

Now, you may enable Lightning Experience without any error.