Why am I receiving a message in saying, "Develop Module disabled?" Already paid.

Lightroom CC 2019?

That is a bit confusing. Are you saying that you have a payed subscription, but that you are still, years later. using LrC v8.2? Is your Windows OS perhaps v7? (or far far worse, v8)

If a Adobe Plan, such as the photography plan, then the following may apply:

1. Close all apps, and Restart your Windows computer. That is a restart not a shutdown.
2. See if LrC then behaves
3. If not. Bring up Adobe.com, sign in. Manage your account, look at your Plan, anything wrong? Is e-mail address associated to your subscription correct?
4. If that is correct, In your Adobe Creative Cloud Desktop App, sign out. then sign in. Keep an eye out for any errors.

see:

• https://helpx.adobe.com/lightroom-classic/kb/develop-module-disabled.html