Hello ZYG123,
Transferring data between accountant and client is a good way to have an accountant check up on client books. QuickBooks Desktop is a robust program that can help you manage your business finances. I can provide some more information.
The only way to convert a .qbx file into a .qba file is within an accountant version of QuickBooks Desktop, so if you're not currently using an accountant version of QuickBooks Desktop that would be why the option is greyed out.
If you're in fact using QuickBooks Desktop Accountant, I would recommend contacting our support team outside of the Community. They'll be able to do some further troubleshooting with you in order to help you get back to converting those files. You can find out how to reach them in this article on QuickBooks Desktop Support Policies.
If you have any questions, feel free to reach out here.
