Hi there! I understand you're having trouble logging into the Newsmax app on your Macintosh running OS X 10.15.7. Let's work through this together.

To start, could you please tell me a bit more about what exactly happens when you try to log in? For example, do you get an error message, or does the app not respond at all?

In the meantime, here are some initial steps we can try to resolve login issues on your Mac browser or app:

1. Try a Different Browser: Sometimes, login problems occur due to browser compatibility. If you're using Safari, try switching to Chrome or Firefox to see if that helps.

2. Clear Your Browser Cache: Sometimes old login data can cause problems. In Safari, you can do this by going to Safari > Preferences > Privacy > Manage Website Data, then remove data related to Newsmax.

3. Verify Your Credentials: Double-check your username and password. It’s easy to mistype, especially with passwords that are case-sensitive.

4. Reset Your Password: If you’re uncertain about your password or it’s not accepted, try using the “Forgot Password” option to reset it.

5. Update Your Browser: Make sure your browser is up-to-date with the latest version compatible with your OS.

6. Check Your Internet Connection: Ensure that your internet is stable.

If you’re using the Newsmax app via a browser on your Mac, these steps usually do the trick.

Because you mentioned OS X 10.15.7, please note that this macOS version is a bit older, but it should still support modern browsers.

If you’re using the Newsmax TV app in some other way (like on a smart TV or a streaming device), let me know so I can guide you accordingly.

Would you like me to guide you step-by-step through clearing your browser cache or resetting your password? Or is there any particular error message you’re seeing?