Allow me to share some information about errors that you're getting and guide you on what to do, Nish12.

The roles that you've created in QuickBooks don't have to do with the error that you're getting. Normally, you'll get this when several users are trying to access QuickBooks at the same time. 

A single-user license only allows one specific person to access QuickBooks from up to two different computers. You'll want to purchase a multi-user license if you want more than two licenses for QuickBooks. This allows a fixed maximum number of users to use QuickBooks at the same time. 

1. In QuickBooks, go to Help then select Manage My License and Buy Additional User License.
   If Buy Additional User License isn't available, your QuickBooks may already be at the maximum number of users allowed.
2. The page that opens gives you the option to buy additional licenses online or by phone. If you choose to use the phone option, you'll be given the phone number to contact Intuit. If you choose to use the online option, a new page will open allowing you to choose the number of licenses you'd like to buy.
3. Install QuickBooks Desktop on additional computers based on the number of licenses you purchased. Use the same license and product numbers you used to originally install QuickBooks Desktop.
4. After installing, follow the prompts to activate QuickBooks Desktop.

Please read this article for more information: Add A User License To Your QuickBooks Software. Furthermore, in case there are errors with your license and product numbers after the purchase, check this article so you'll be guided: Fix Activation, License, And Product Number Errors. 

Keep in touch if you have any questions about the error. I'm always right here to help.